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Editor’s Choice Articles

Editor’s Choice articles are based on recommendations by the scientific editors of MDPI journals from around the world. Editors select a small number of articles recently published in the journal that they believe will be particularly interesting to readers, or important in the respective research area. The aim is to provide a snapshot of some of the most exciting work published in the various research areas of the journal.

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24 pages, 697 KB  
Review
Carnosic Acid and Carnosol: Analytical Methods for Their Determination in Plants, Foods and Biological Samples
by Christiana Mantzourani, Petros A. Tarantilis and Maroula G. Kokotou
Separations 2023, 10(9), 481; https://doi.org/10.3390/separations10090481 - 2 Sep 2023
Cited by 6 | Viewed by 8929
Abstract
Among the various phytochemicals, which are present in Lamiaceae plants, carnosic acid and carnosol stand out. Carnosic acid is a phenolic diterpene carrying two phenolic hydroxyl groups and a carboxyl group, while carnosol carries a lactone moiety in addition to phenolic hydroxyls. Both [...] Read more.
Among the various phytochemicals, which are present in Lamiaceae plants, carnosic acid and carnosol stand out. Carnosic acid is a phenolic diterpene carrying two phenolic hydroxyl groups and a carboxyl group, while carnosol carries a lactone moiety in addition to phenolic hydroxyls. Both these phenolic diterpenes exhibit interesting biological properties, such as antioxidant, anticancer, anti-inflammatory and neuroprotective activities. In this review, we summarize the existing analytical methods for the determination of carnosic acid and carnosol, primarily in plants, but also in foods and biological samples. Due to the biological importance of carnosic acid and carnosol, a variety of analytical methods, including high-performance liquid chromatography–ultra violet (HPLC–UV), liquid chromatography–mass spectrometry (LC–MS) and capillary electrophoresis (CE), were developed for their determination. In addition, we discuss the extraction methods applied for their isolation from plants and in brief the bioactivities of these phytochemicals. Full article
(This article belongs to the Special Issue Application of Chromatography in Pharmaceutical and Biomedical Analysis)
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19 pages, 3311 KB  
Article
Potential Use of Agricultural Waste—Carob Kibbles (Ceratonia siliqua L.) as a Biosorbent for Removing Boron from Wastewater
by Luz Adriana Díaz, Jorge Dias Carlier, Izabela Michalak and María Clara Costa
Separations 2023, 10(9), 464; https://doi.org/10.3390/separations10090464 - 24 Aug 2023
Cited by 2 | Viewed by 2068
Abstract
The release of boron (B) into the environment as a result of anthropogenic activity modifies sustainable natural conditions, thus affecting ecosystems. To meet water quality regulations, commercial and natural boron adsorbents are available to reduce its concentrations in industrial effluents, with the former [...] Read more.
The release of boron (B) into the environment as a result of anthropogenic activity modifies sustainable natural conditions, thus affecting ecosystems. To meet water quality regulations, commercial and natural boron adsorbents are available to reduce its concentrations in industrial effluents, with the former being not only more expensive but also less sustainable. In the publication, the biosorption parameters of carob kibbles (Ceratonia siliqua L.) were optimized in order to remove boron from aqueous solutions using batch experiments. The biosorbent used in the present research was agro-waste biomass provided by the local locust-beam gum industry. Boron removal by carob kibbles was favored at high initial pH values, and this capacity was found to be a function of boron initial concentration, biosorbent content in the solution, and particle size. The change in temperature did not affect the potential of biomass to remove boron. The highest boron removal efficiency (55.1%) was achieved under the following optimal conditions: 50 g/L biosorbent dose (Cs), with particle size range 0.025–0.106 mm, for the initial concentration (C0) of boron in the solution of 100 mg/L, at an initial pH of 11.5, for 5 h at 25 °C. This investigation suggests that carob kibble agro-waste can be valorized as a biosorbent to remove boron from wastewater, and the boron-loaded residue may eventually be explored as a new boron-fertilizer. Full article
(This article belongs to the Special Issue (Bio)-Sorbents for Water Treatment and Soil Remediation)
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19 pages, 5711 KB  
Article
Carob Pulp Flour Extract Obtained by a Microwave-Assisted Extraction Technique: A Prospective Antioxidant and Antimicrobial Agent
by Jana Zahorec, Dragana Šoronja-Simović, Sunčica Kocić-Tanackov, Sandra Bulut, Nikola Martić, Katarina Bijelić, Danica Božović and Branimir Pavlić
Separations 2023, 10(9), 465; https://doi.org/10.3390/separations10090465 - 24 Aug 2023
Cited by 7 | Viewed by 2282
Abstract
In this study, carob pulp flour (CF) extract was characterized as a high-value antioxidant and antimicrobial agent. CF extracts were obtained using microwave-assisted extraction (MAE) and optimization of the MAE process was accomplished using response surface methodology. The studied processing parameters of MAE [...] Read more.
In this study, carob pulp flour (CF) extract was characterized as a high-value antioxidant and antimicrobial agent. CF extracts were obtained using microwave-assisted extraction (MAE) and optimization of the MAE process was accomplished using response surface methodology. The studied processing parameters of MAE were the liquid/solid (L/S) ratio (10–30 mL/g), extraction time (15–35 min), and ethanol concentration (40–80% w/w). The efficiency of the extraction of valuable compounds from CF was evaluated by the determining extraction yield (Y), total phenolic(TP), total flavonoid (TF) content, and antioxidant activity (DPPH, FRAP, and ABTS). The optimized MAE parameters for maximizing the yields of target compounds and antioxidant activity were the L/S ratio 30 mL/g, extraction time 35 min, and ethanol concentration 40%. The experimentally obtained values for TP, TF, DPPH, FRAP, and ABTS were 1609.92 GAE/100 g, 271.92 CE/100 g, 99.02 µMTE/g, 50.45 µM Fe2+/g, and 110.55 µMTE/g, respectively. The optimized CF extract was compared with the CF extracts obtained by conventional solid–liquid extraction (S/L) and ultrasound-assisted extraction (UAE) and was found to be more beneficial due to a 30% higher yield of TP and TF and 30–80% higher antioxidant activity. The phenolic profiles of the three extracts were quite similar. The microdilution method confirmed the antibacterial activity of MAE and S/L extracts while the antifungal effect was not observed. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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22 pages, 7059 KB  
Review
Fluoride Removal from Water Sources by Adsorption on MOFs
by Athanasia K. Tolkou and Anastasios I. Zouboulis
Separations 2023, 10(9), 467; https://doi.org/10.3390/separations10090467 - 24 Aug 2023
Cited by 21 | Viewed by 4669
Abstract
Fluoride is present in several groundwaters due to natural or anthropogenic origins. Although it is necessary for physiological human functions (in small amounts, i.e., 0.5–1.2 mg/L), it could be very harmful when it exceeds the maximum permissible concentration limit of 1.5 mg/L (according [...] Read more.
Fluoride is present in several groundwaters due to natural or anthropogenic origins. Although it is necessary for physiological human functions (in small amounts, i.e., 0.5–1.2 mg/L), it could be very harmful when it exceeds the maximum permissible concentration limit of 1.5 mg/L (according to WHO). Among the numerous technologies for removing fluoride from waters, metal–organic framework (MOF) materials are considered to be promising adsorbents due to their advantages of high porosity, high specific surface area, diverse functions and easy modification. In this study, the synthesis of MOFs and the progress of their application to the removal of fluoride from contaminated water, as published in the recent literature mainly over the past five years, are reviewed. The adsorption mechanism(s) and its main characteristics, such as effect of initial fluoride concentration, adsorbent dosage, solution pH, contact time, adsorption capacity, thermodynamic and regeneration studies, etc., for the removal of fluoride with the addition of different MOFs are compared. According to these comparisons, the hydrothermal/solvothermal synthesis method is most commonly used for the preparation of MOFs, whereas higher BET surface areas are shown by specific MOFs based on aluminum metal ions. The main fluoride adsorption mechanisms were found to be electrostatic attraction and/or complexation. The most common pH for conducting experiments was 7.0, but several examined materials were found to be effective over a wide pH range. Four to six regeneration cycles were successfully applied on average, regarding the MOFs under review, whereas in the majority of these cases, the sorption process was found to be endothermic. Full article
(This article belongs to the Special Issue Development of Mesoporous Materials for Adsorption and Recovery of Metals)
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22 pages, 1095 KB  
Review
Adsorption-Based Pretreatment of Irrigation Water to Prevent Water Quality Issues
by Tamás Kucserka, Gábor István Németh, Ivett Pálfi, Zsolt L. Kiss, Etelka Tombácz and Ildikó Galambos
Separations 2023, 10(9), 468; https://doi.org/10.3390/separations10090468 - 24 Aug 2023
Cited by 4 | Viewed by 2677
Abstract
Access to and the use of irrigation water of adequate quality and targeted nutrient supplementation have become more widespread in recent years. Both crop quality and the irrigation system lifetime are affected by the quality of the water used for irrigation. Micro-irrigation (e.g., [...] Read more.
Access to and the use of irrigation water of adequate quality and targeted nutrient supplementation have become more widespread in recent years. Both crop quality and the irrigation system lifetime are affected by the quality of the water used for irrigation. Micro-irrigation (e.g., drip and sprinkle) is becoming increasingly common alongside the more typical irrigation methods, but it requires expertise and pre-treatment to ensure a proper water supply. The most significant problem is clogging, which can greatly reduce irrigation efficiency. Treatment for irrigation purposes mainly depends on the contaminants that are present in the water. The main treatment options available are biological, electromagnetic and electrostatic treatments, but these have a wide range of effectiveness levels compared to membrane separation technologies. In addition, adsorption treatments are also available, which, depending on the adsorbent used, can greatly improve the pre-treatment of irrigation water. This work provides an overview of adsorbents suitable for the treatment of irrigation water and their effectiveness. The separation of interfering components via adsorption is effective and promising for future application as the expected irrigation demands increase. Full article
(This article belongs to the Topic Sustainable Water Purification Technologies for Multiple Applications)
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17 pages, 800 KB  
Article
Solid–Liquid Extraction of Bioactive Molecules from White Grape Skin: Optimization and Near-Infrared Spectroscopy
by Tea Sokač Cvetnić, Korina Krog, Maja Benković, Tamara Jurina, Davor Valinger, Jasenka Gajdoš Kljusurić, Ivana Radojčić Redovniković and Ana Jurinjak Tušek
Separations 2023, 10(8), 452; https://doi.org/10.3390/separations10080452 - 14 Aug 2023
Cited by 6 | Viewed by 2342
Abstract
In this work, the solid–liquid extraction of bioactive molecules from grape skin was performed using water as the extraction solvent. The effects of extraction time (t = 60, 75, and 90 min), extraction temperature (T = 40, 60, and 80 °C), [...] Read more.
In this work, the solid–liquid extraction of bioactive molecules from grape skin was performed using water as the extraction solvent. The effects of extraction time (t = 60, 75, and 90 min), extraction temperature (T = 40, 60, and 80 °C), solid–liquid phase ratio (S/L = 10, 20, and 30 g/L), and mixing speed (rpm = 250, 500, and 750 1/min) on the total dissolved solids, extraction yield, concentration of total polyphenols, and antioxidant activity were determined using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) methods. According to response surface modeling, the optimal extraction conditions were t = 75 min, T = 80 °C, S/L = 30 g/L, and rpm = 750 1/min, and under optimal process conditions, 8.38 mgGAE/gd.m. was obtained. Furthermore, the potential of near-infrared (NIR) spectroscopy coupled with artificial neural network (ANN) modeling for prediction of the physical and chemical properties of prepared extracts was also analyzed. The use of ANN modeling demonstrated highly favorable correlations between the NIR spectra and all the variables tested, particularly the total dissolved solids (TDS) and antioxidant activity measured using the FRAP method. As a result, ANN modeling proved to be a valuable tool for predicting the concentration of total polyphenols, the antioxidant activity, and the extraction yield of a plant extract based on its NIR spectra. Full article
(This article belongs to the Section Bioanalysis/Clinical Analysis)
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18 pages, 1141 KB  
Article
The Development and Validation of a Targeted LC-HRAM-MS/MS Methodology to Separate and Quantify p-Synephrine and m-Synephrine in Dietary Supplements and Herbal Preparations
by Celine Vanhee, Sophia Barhdadi, Angélique Kamugisha, Tanika Van Mulders, Kevin Vanbrusselen, Marie Willocx and Eric Deconinck
Separations 2023, 10(8), 444; https://doi.org/10.3390/separations10080444 - 9 Aug 2023
Cited by 5 | Viewed by 2999
Abstract
Dietary supplements containing Citrus aurantium or p-synephrine remain very popular in Europe and the United States of America (USA). They are primarily sold as weight loss enhancers, although their efficacy and the safety are still under scrutiny. To this end, several countries [...] Read more.
Dietary supplements containing Citrus aurantium or p-synephrine remain very popular in Europe and the United States of America (USA). They are primarily sold as weight loss enhancers, although their efficacy and the safety are still under scrutiny. To this end, several countries have set maximum threshold levels of p-synephrine that are permitted in dietary supplements. Moreover, there have also been reports of possible chemical adulteration of these supplements with the synthetic positional isomer, m-synephrine, known to be used as a medicinal product. Therefore, it is pivotal for regulatory agencies to be able to discriminate between the two positional isomers and also quantify the amount of each when encountered in dietary supplements. Here, we present the development and the validation of a simple and fast “dilute and shoot” procedure, employing liquid chromatographic (LC) separation in combination with high-resolution accurate mass (HRAM) tandem mass spectroscopy (LC-HRAM-MS/MS) to separate these two isomers and subsequently quantify them. The quantification methodology has been validated using the “total error approach”, applying accuracy profiles, and is consequently compliant with ISO17025. Moreover, ten real-life samples, either purchased online or encountered by Belgian regulatory agencies, were analyzed using the described procedure. Startlingly, only one sample out of ten was compliant with Belgian legislation in terms of labeling, the presence of a batch number, expiration date and dosage (with a tolerated error of ±20%). Moreover, three samples also contained banned substances such as yohimbine and sibutramine. Full article
(This article belongs to the Special Issue Recent Advances and Trends in Dietary Supplement Analysis)
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24 pages, 4875 KB  
Article
Biosynthesis of Salbutamol-4′-O-sulfate as Reference for Identification of Intake Routes and Enantiopure Salbutamol Administration by Achiral UHPLC-MS/MS
by Annika Lisa Jendretzki, Lukas Corbinian Harps, Yanan Sun, Felix Bredendiek, Matthias Bureik, Ulrich Girreser, Xavier de la Torre, Francesco M. Botrè and Maria Kristina Parr
Separations 2023, 10(8), 427; https://doi.org/10.3390/separations10080427 - 28 Jul 2023
Cited by 1 | Viewed by 4345
Abstract
The aim of the study was a comprehensive and quantitative determination of salbutamol and its sulfoconjugated major metabolite in urine samples using achiral ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Therefore, salbutamol-4′-O-sulfate was biosynthesized as a reference using genetically modified fission [...] Read more.
The aim of the study was a comprehensive and quantitative determination of salbutamol and its sulfoconjugated major metabolite in urine samples using achiral ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Therefore, salbutamol-4′-O-sulfate was biosynthesized as a reference using genetically modified fission yeast cells, and the product was subsequently characterized by NMR and HRMS. In competitive sports, salbutamol is classified as a prohibited drug; however, inhalation at therapeutic doses is permitted with a maximum allowance of 600 µg/8 h. In contrast, the enantiopure levosalbutamol is prohibited under any condition. For analytical discrimination, the amount of salbutamol and its main metabolite excreted in the urine was studied. As proof of concept, a longitudinal study in one healthy volunteer was performed in order to investigate excreted amounts and to study potential discrimination using achiral chromatography. Discrimination of administration of racemic salbutamol or the enantiopure levosalbutamol was not achieved by solely analyzing salbutamol as the parent compound. However, a distinction was possible by evaluation of the proportion of salbutamol-4′-O-sulfate in relation to salbutamol. Therefore, reference material of metabolites is of great importance in doping control, especially for threshold substances. Full article
(This article belongs to the Special Issue Application of Hyphenated Techniques in Bioanalysis and Metabolite Identification)
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19 pages, 1119 KB  
Article
Phytochemical Profile, Antioxidant Activity and Cholinesterase Inhibition Potential of Essential Oil and Extracts of Teucrium montanum from Bosnia and Herzegovina
by Mejra Bektasevic, Mladenka Jurin, Marin Roje and Olivera Politeo
Separations 2023, 10(8), 421; https://doi.org/10.3390/separations10080421 - 26 Jul 2023
Cited by 15 | Viewed by 3607
Abstract
Bioactive compounds from plants play an important role in slowing many neurodegenerative diseases, such as Alzheimer’s disease, by inhibiting cholinesterase enzymes. Studies have shown that oxidative stress is associated with the development of Alzheimer’s disease. In traditional medicine of Bosnia and Herzegovina, Teucrium [...] Read more.
Bioactive compounds from plants play an important role in slowing many neurodegenerative diseases, such as Alzheimer’s disease, by inhibiting cholinesterase enzymes. Studies have shown that oxidative stress is associated with the development of Alzheimer’s disease. In traditional medicine of Bosnia and Herzegovina, Teucrium montanum is used to treat numerous diseases. The chemical composition and biological activity of the essential oil (EO) and aqueous (AE) and methanol extract (ME) of this plant were studied. The chemical composition of EO was studied using GC-MS, while the composition of the extracts was studied using HPLC-DAD. Antioxidant activity was tested using the DPPH and FRAP methods. The protection of lipids and proteins from oxidation was tested using the ammonium thiocyanate and BSA oxidation methods. The ability to inhibit cholinesterases was tested by the Ellman method. The main identified EO compounds were α-cadinol, ß-selinene, δ-cadinene, epi-α-cadinol, germacrene D-4-ol, and α-pinene. The main phenolic compounds of the extracts were p-coumaric acid, ellagic acid and caffeic acid. The tested extracts showed good antioxidant radical scavenging and reducing potential and a very good ability to protect lipids and proteins from oxidation. The EO showed moderate AChE and BChE inhibition potential, while the extracts showed weak or no ability. Full article
(This article belongs to the Special Issue Separation, Analysis and Biological Evaluation of Bioactive Compounds)
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18 pages, 3155 KB  
Review
Advances in Cork Use in Adsorption Applications: An Overview of the Last Decade of Research
by João Jesus, Raquel Nunes da Silva and Ariana Pintor
Separations 2023, 10(7), 390; https://doi.org/10.3390/separations10070390 - 3 Jul 2023
Cited by 10 | Viewed by 3766
Abstract
Cork-based adsorbents have been gathering interest from the research community since the 1990s. A first review was published on this topic in 2012. Still, in the last decade, novel activated carbons and biochars, in multiple applications, have been produced using cork as a [...] Read more.
Cork-based adsorbents have been gathering interest from the research community since the 1990s. A first review was published on this topic in 2012. Still, in the last decade, novel activated carbons and biochars, in multiple applications, have been produced using cork as a raw material. This review presents these novel insights into the properties of cork, in its various forms, and how they relate to adsorption capacity. Details on new preparation methodologies and respective characteristics of cork-based activated carbons and biochars are thoroughly compared, and patterns are identified. Finally, the adsorption capacity of these materials in experimental conditions is reviewed for different compounds: heavy metals, organics, and gaseous pollutants. This review provides a complete picture of the kind and quality of different cork forms, their relative economic value, and how their conversion into activated carbons and biochars can contribute to a more circular economy by producing adsorbents that aid in the reduction of multiple pollution types. Full article
(This article belongs to the Special Issue Removal of Metals or Other Toxic Substances from Wastewaters by Natural Sorbents)
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23 pages, 2691 KB  
Article
Quantitation of Formoterol, Salbutamol, and Salbutamol-4′-O-Sulfate in Human Urine and Serum via UHPLC-MS/MS
by Lukas C. Harps, Daniel A. Bizjak, Ulrich Girreser, Martina Zügel, Jürgen M. Steinacker, Patrick Diel and Maria Kristina Parr
Separations 2023, 10(7), 368; https://doi.org/10.3390/separations10070368 - 22 Jun 2023
Cited by 7 | Viewed by 2480
Abstract
The adrenergic beta-2 agonists formoterol and salbutamol are used for the treatment of asthma and COPD but are also misused in sports competitions. Therefore, they are included in WADA regulations. Both drugs are mainly excreted in urine after administration via inhalation. A four-armed, [...] Read more.
The adrenergic beta-2 agonists formoterol and salbutamol are used for the treatment of asthma and COPD but are also misused in sports competitions. Therefore, they are included in WADA regulations. Both drugs are mainly excreted in urine after administration via inhalation. A four-armed, double-blind cross-over clinical trial was conducted involving endurance-trained participants (12 females and 12 males). Inhalation dosages of 36 μg formoterol, 1200 μg salbutamol, a combination of both, or a placebo were administered before exercise. Serum and urine were collected after exercise and 3 and 24 h after administration. Here, we show the successful quantitation of formoterol, salbutamol, and its phase II metabolite salbutamol-4′-O-sulfate in all urine and serum samples using ultra-high performance liquid chromatography–tandem mass spectrometry. In the serum analysis, results of up to 14.2 pg/mL formoterol, 10.0 ng/mL salbutamol, and 21.4 ng/mL salbutamol-4′-O-sulfate (calculated as salbutamol equivalent) were found. In urine, maximum concentrations (after deglucuronidation) were 17.2 ng/mL formoterol, 948.5 ng/mL salbutamol, and 2738.5 ng/mL salbutamol-4′-O-sulfate. Sex-specific differences in serum concentrations as well as in urinary excretion were observed. The results pronounce the importance of the implementation and elucidation of phase II metabolites to quantitation methods in antidoping. Full article
(This article belongs to the Special Issue Application of Hyphenated Techniques in Bioanalysis and Metabolite Identification)
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17 pages, 1837 KB  
Article
Comprehensive Metabolite Fingerprinting of Australian Black and Green Olives and Their Antioxidant and Pharmacokinetics Properties
by Akhtar Ali, Farhad Ahmadi, Jeremy J. Cottrell and Frank R. Dunshea
Separations 2023, 10(6), 354; https://doi.org/10.3390/separations10060354 - 13 Jun 2023
Cited by 10 | Viewed by 3326
Abstract
Polyphenols, especially flavonoids, are well-known for their bioactive antioxidant properties. Therefore, this study aimed to analyze Australian black (ripe) and green olives (unripe) for phenolic and non-phenolic metabolites, antioxidant activities, and pharmacokinetic properties. Liquid chromatography–mass spectrometry coupled with quadrupole–time of flight (LC–ESI–QTOF–MS/MS) was [...] Read more.
Polyphenols, especially flavonoids, are well-known for their bioactive antioxidant properties. Therefore, this study aimed to analyze Australian black (ripe) and green olives (unripe) for phenolic and non-phenolic metabolites, antioxidant activities, and pharmacokinetic properties. Liquid chromatography–mass spectrometry coupled with quadrupole–time of flight (LC–ESI–QTOF–MS/MS) was applied to elucidate the composition, identification, and characterization of bioactive metabolites from Australian olives. This study identified 110 metabolites, including phenolic acids, flavonoids, stilbenes, lignans, and other compounds (phenolic terpenes, tyrosols, fatty acids, and terpenoids). Luteolin (flavonoid) and verbascoside (hydroxycinnamic acid) are identified with higher concentrations in black olives. Black (ripe) olives were measured at a higher TPC (10.94 ± 0.42 mg GAE/g) and total antioxidant potential than green olives. The pharmacokinetic properties (absorption, distribution, metabolism, excretion, toxicity) of phenolic compounds for human health were evaluated to predict the potential of the most abundant metabolites in olives. Gastrointestinal absorption and Caco-2 cell permeability of metabolites in olives were also predicted. This study will develop into further research to identify the Australian olives’ therapeutic, nutraceutical, and phytopharmaceutical potential. Full article
(This article belongs to the Special Issue Isolation, Elucidation and Synthesis of Bioactive Natural Products)
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17 pages, 1070 KB  
Article
Particle Cut Diameter Prediction of Uniflow Cyclone Systems with Fuzzy System Analysis
by Vinzenz Klapper, Giovanni Luzi, Benedict Prah and Antonio Delgado
Separations 2023, 10(6), 345; https://doi.org/10.3390/separations10060345 - 5 Jun 2023
Cited by 1 | Viewed by 3954
Abstract
Cyclones are devices used in various industries to remove particulate matter from gases and liquids. Commonly used in the power generation, cement, and mining industries, cyclones improve the efficiency and longevity of equipment by removing dust and other small particles that can cause [...] Read more.
Cyclones are devices used in various industries to remove particulate matter from gases and liquids. Commonly used in the power generation, cement, and mining industries, cyclones improve the efficiency and longevity of equipment by removing dust and other small particles that can cause wear and damage. Among centrifugal separation, reverse-flow cyclones are primarily used for particle separation, which can reach heights of several meters on an industrial scale and therefore, are difficult to access for maintenance. A uniflow centrifugal segregation system avoids these drawbacks of reverse-flow cyclones since their accessibility is good and their height usually does not exceed their diameter. The efficiency is a critical aspect of separating systems. This study systematically examines the collection efficiency for particles ranging from 1 μm to 29 μm in diameter based on varying vane angles of the swirl inducer at flow rates ranging from 130 Ls−1 to 236 Ls−1. Full article
(This article belongs to the Collection Feature Paper Collection in Section 'Purification Technology')
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19 pages, 8233 KB  
Article
Particulate Matter Detachment from a Magnetizable Single Fiber Applying Magnetic Forces in Ambient Air
by Julia Szabadi, Jörg Meyer and Achim Dittler
Separations 2023, 10(5), 297; https://doi.org/10.3390/separations10050297 - 7 May 2023
Cited by 2 | Viewed by 2071
Abstract
The potential utilization of magnetic effects in gas particle separation is a current subject of research. This paper demonstrates for the first time that a single magnetizable filter fiber can be deflected by a magnetically induced excitation for a selected combination of parameters, [...] Read more.
The potential utilization of magnetic effects in gas particle separation is a current subject of research. This paper demonstrates for the first time that a single magnetizable filter fiber can be deflected by a magnetically induced excitation for a selected combination of parameters, resulting in the removal of deposited particle structures with high detachment levels. A correlation between the magnetic flux density and achieved acceleration to overcome the adhesive forces/strength of the particle structure was determined. The degree of detachment after each regeneration was calculated by comparing the projection area before and after detachment using high-speed images. At a magnetic flux density of B = 38.5 mT, accelerations of maximum a = 105 m·s−2 are achieved, depending on the axial position along the single fiber. The degrees of regeneration achieved at these parameters depend on the amount of fiber loading and on the fiber orientation in the gravitational field. The horizontal orientation of the fiber leads to an increased reattachment of precedingly detached particle structures after deflection compared to a vertical orientation. High particle loading on the fiber results in enhanced detachment by inertia. Under the most favorable process conditions investigated, detachment levels of >90% are achieved. Full article
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23 pages, 3386 KB  
Article
Comparative Study of Conventional, Microwave-Assisted and Supercritical Fluid Extraction of Bioactive Compounds from Microalgae: The Case of Scenedesmus obliquus
by Ioulia Georgiopoulou, Vasiliki Louli and Kostis Magoulas
Separations 2023, 10(5), 290; https://doi.org/10.3390/separations10050290 - 4 May 2023
Cited by 16 | Viewed by 3753
Abstract
The recovery of bioactive products with green processes is a critical topic for the research and industry fields. In this work, the application of solid–liquid (SLE), microwave-assisted extraction (MAE) with aq. ethanol 90% v/v and supercritical fluid extraction (SFE) with CO [...] Read more.
The recovery of bioactive products with green processes is a critical topic for the research and industry fields. In this work, the application of solid–liquid (SLE), microwave-assisted extraction (MAE) with aq. ethanol 90% v/v and supercritical fluid extraction (SFE) with CO2 for the recovery of biocomponents from Scenedesmus obliquus is studied. The effects examined were temperature (30–60 °C), time (6–24 h), and solvent-to-biomass ratio (20–90 mLsolv/gbiom) for SLE, temperature (40–60 °C), time (5–25 min), solvent-to-biomass ratio (20–90 mLsolv/gbiom), and microwave power (300–800 W) for MAE, and temperature (40–60 °C), pressure (110–250 bar), solvent flow rate (20–40 gsolv/min), and cosolvent presence (0, 10% w/w ethanol) for SFE in relation to the extract’s yield, phenolic, chlorophyll, carotenoid content, and antioxidant activity. The optimum extraction conditions determined were 30 °C, 24 h, and 90 mLsolv/gbiom for SLE, 60 °C, 5 min, 90 mLsolv/gbiom, and 300 W for MAE, and 60 °C, 250 bar, and 40 gsolv/min for SFE. Additionally, a kinetic SFE study was conducted and the obtained results were satisfactorily correlated using Sovová’s model. The comparison between the methods proved MAE’s efficiency in all terms compared to SLE. Moreover, SFE was accompanied with the lowest yield and chlorophyll content, yet led to an increased carotenoid content and improved antioxidant activity. Finally, the cosolvent addition significantly improved SFE’s yield and led to the most superior extract. Full article
(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)
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19 pages, 4166 KB  
Article
Improvement of Gd(III) Solvent Extraction by 4-Benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one: Non-Aqueous Systems
by Maria Atanassova and Rositsa Kukeva
Separations 2023, 10(5), 286; https://doi.org/10.3390/separations10050286 - 3 May 2023
Cited by 5 | Viewed by 2670
Abstract
The study of the liquid–liquid extraction of gadolinium (Gd(III) ion) with a chelating compound, 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HP), and the determination of the process parameters are presented by employing two ionic liquids, namely, ([C1Cnim+][Tf2N−], n [...] Read more.
The study of the liquid–liquid extraction of gadolinium (Gd(III) ion) with a chelating compound, 4-benzoyl-3-methyl-1-phenyl-2-pyrazolin-5-one (HP), and the determination of the process parameters are presented by employing two ionic liquids, namely, ([C1Cnim+][Tf2N−], n = 4, 10) and CHCl3, as diluents. Compared to CHCl3, the ionic liquid offers increased distribution ratios in an aqueous medium. A step forward, enhanced solvent extraction, and improved separation upon the addition of ethylene glycol are demonstrated, i.e., a boost of two immiscible organic phases, compared to traditional aqueous solutions. However, this is noticeable when using CHCl3, but unfortunately not with ionic liquid combination, [C1C10im+][Tf2N−]. Several conclusions are given, highlighting the role of the ionic diluent in complexation processes and selectivity with an employment of the chelating agent HP for various metal s-, p-, d-, and f-cations, i.e., nearly 25 metals. A detailed evaluation of the selectivity between these metals was made when changing both the aqueous phase completely with ethylene glycol or partially with glycerol (1:1). Electron paramagnetic resonance (EPR) spectroscopy has been used to study the established chemical species in the obtained organic extracts, such as Gd3+, Fe3+, Cu2+, and Cr3+, with unpaired electrons. Full article
(This article belongs to the Topic Green Twist in Solvent Extraction and Separation of Metal Species)
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18 pages, 2583 KB  
Article
Method Development and Validation for the Simultaneous Quantitation of Pentoxifylline, Its Pharmacologically Active Metabolites, and Donepezil Using LC-MS/MS in Rat Plasma: Its Application to a Pharmacokinetic Study
by Sanghee Choi, Wang-Seob Shim, Jiyoung Yoon, Doowon Choi, Eunseo Song, Yeo Jin Choi, Soo-Heui Paik and Kyung-Tae Lee
Separations 2023, 10(5), 276; https://doi.org/10.3390/separations10050276 - 24 Apr 2023
Cited by 5 | Viewed by 2813
Abstract
This study developed a simple, rapid, reproducible, and analytical method using liquid chromatography and electrospray ionization (ESI) with tandem mass spectrometry (LC-MS/MS) to simultaneously quantify pentoxifylline (PTX), its pharmacological active metabolites, lisofylline (PTX-M1) and 1-(3-carboxypropyl)-3,7-dimethylxanthine (PTX-M5), and donepezil (DNP) in rat plasma, using [...] Read more.
This study developed a simple, rapid, reproducible, and analytical method using liquid chromatography and electrospray ionization (ESI) with tandem mass spectrometry (LC-MS/MS) to simultaneously quantify pentoxifylline (PTX), its pharmacological active metabolites, lisofylline (PTX-M1) and 1-(3-carboxypropyl)-3,7-dimethylxanthine (PTX-M5), and donepezil (DNP) in rat plasma, using PTX-d6 and DNP-d7 as the internal standards. The LC-MS/MS procedure was performed at the ESI interface, operating in positive ionization and multiple reaction monitoring (MRM) modes; the monitoring of transitions comprised m/z 279.3 > 181.1 for PTX, m/z 281.1 > 263.1 > 160.90 for PTX-M1, m/z 267.1 > 249.0 > 220.9 for PTX-M5, m/z 380.3 > 90.9 for DNP, m/z 285.3 > 187.1 for PTX-d6 (IS1), and m/z 387.3 > 98.3 for DNP-d7 (IS2). After plasma protein precipitation (PP) with methanol, chromatographic separation was performed with an Imtakt Cadenza® CD-C18 (100 × 3 mm, 3 µm) column, using an isocratic mobile phase consisting of 0.1% formic acid in water and methanol (20:80, v/v) at a flow rate of 0.2 mL/min. The retention times of DNP, PTX-M5, PTX, and PTX-M1 were 2.24, 2.50, 2.68, and 2.72 min, respectively, with a total run time of 5 min. This method was validated over a linear concentration range of 5–8000, 10–5000, 20–15,000, and 2–500 ng mL−1 for PTX, PTX-M1, PTX-M5, and DNP, respectively, with a high correlation coefficient (r2 ≥ 0.99). The established method was fully validated in terms of selectivity, the lower limit of quantitation, precision, accuracy, recovery, matrix effect, stability, and dilution integrity according to the regulatory guidelines from the U.S. Food and Drug Administration and the Korea Ministry of Food and Drug Safety. The validated method was successfully applied to a pharmacokinetic study on the concurrent administration of DNP and PTX in rats. Full article
(This article belongs to the Section Bioanalysis/Clinical Analysis)
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15 pages, 934 KB  
Article
Cucumis metuliferus L. Fruits Extract with Antioxidant, Anti-Inflammatory, and Antidiabetic Properties as Source of Ursolic Acid
by Anna Cazanevscaia Busuioc, Giorgiana Valentina Costea, Andreea Veronica Dediu Botezatu, Bianca Furdui and Rodica Mihaela Dinica
Separations 2023, 10(5), 274; https://doi.org/10.3390/separations10050274 - 23 Apr 2023
Cited by 7 | Viewed by 3405
Abstract
To identify healthy, nutritious, and sustainable plant-based products rich in biologically active compounds, this present study was conducted, and the phytochemical composition and biological properties of the hydroethanolic ultrasound-assisted extract of the fruits of Cucumis metuliferus were investigated. Cucumis metuliferus is an unexplored [...] Read more.
To identify healthy, nutritious, and sustainable plant-based products rich in biologically active compounds, this present study was conducted, and the phytochemical composition and biological properties of the hydroethanolic ultrasound-assisted extract of the fruits of Cucumis metuliferus were investigated. Cucumis metuliferus is an unexplored fruit of a climbing plant in the Cucurbitaceae family, widely distributed in the tropical and subtropical regions of sub-Saharan Africa and whose nutritional and medicinal benefits are well known in African countries, especially. Therefore, its cultivation in other regions could influence chemical composition. The structural identification of the compounds from the hydroethanolic extract from Cucumis metuliferus fruits grown in Romania was carried out by chromatographic techniques (HPLC). The main compounds identified were catechin, oleanolic acid, ursolic acid, p-coumaric acid, and epicatechin. Subsequently, a method was proposed to isolate and characterize ursolic acid, one of the major compounds. The obtained results show that the hydroethanolic extract is rich in antioxidant compounds evaluated using the DPPH radical inhibition method (IC50 = 32.74 ± 0.02 µg/mL) and ABTS cation radical inhibition method (IC50 = 11.37 ± 0.07 µg/mL). It also demonstrate in vitro anti-inflammatory activities, such as anti-lipoxygenase (IC50 = 32.90 ± 0.05 µg/mL) and anti-proteinase (IC50 = 16.34 ± 0.07 µg/mL), and antidiabetic properties by inhibiting α-amylase (IC50 = 429.541 ± 0.25 µg/mL) and β-glucosidase activity (IC50 = 385.685 ± 0.76 µg/mL). Therefore, C. metuliferus fruits could be effectively used in the development of various health-promoting products, being not only appetizing, with spectacular appearance and with extended storage life, but also curative and healthy. Full article
(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)
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30 pages, 3393 KB  
Review
Mass Transfer and Droplet Behaviors in Liquid-Liquid Extraction Process Based on Multi-Scale Perspective: A Review
by Sicen Yu, Jiyizhe Zhang, Shaowei Li, Zhuo Chen and Yundong Wang
Separations 2023, 10(4), 264; https://doi.org/10.3390/separations10040264 - 18 Apr 2023
Cited by 23 | Viewed by 12220
Abstract
Liquid-liquid extraction is an important separation technology in the chemical industry, and its separation efficiency depends on thermodynamics (two-phase equilibrium), hydrodynamics (two-phase mixing and contact), and mass transfer (molecular diffusion). For hydrodynamics, the dispersion size of droplets reflects the mixing of two phases [...] Read more.
Liquid-liquid extraction is an important separation technology in the chemical industry, and its separation efficiency depends on thermodynamics (two-phase equilibrium), hydrodynamics (two-phase mixing and contact), and mass transfer (molecular diffusion). For hydrodynamics, the dispersion size of droplets reflects the mixing of two phases and determines the mass transfer contact area of the two phases. Therefore, a deep understanding of the droplet dispersion mechanism can help guide process intensification. The mass transfer and droplet behaviors in the liquid-liquid extraction process are reviewed based on three scales: equipment, droplets, and the interface between two liquids. Studies on the interaction between mass transfer and other performance parameters in extraction equipment as well as liquid-liquid two-phase flow models are reviewed at the equipment scale. The behaviors of droplet breakage and coalescence and the kernel function of the population balance equation are reviewed at the droplet scale. Studies on dynamic interfacial tension and interaction between interfaces are reviewed at the interface scale. Finally, the connection among each scale is summarized, the existing problems are analyzed, and some future research directions are proposed in the last section. Full article
(This article belongs to the Special Issue Advances in Separation Engineering)
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15 pages, 3373 KB  
Article
Characterization and Photocatalytic Performance of Newly Synthesized ZnO Nanoparticles for Environmental Organic Pollutants Removal from Water System
by Vesna Despotović, Nina Finčur, Sabolč Bognar, Daniela Šojić Merkulov, Predrag Putnik, Biljana Abramović and Sanja Panić
Separations 2023, 10(4), 258; https://doi.org/10.3390/separations10040258 - 16 Apr 2023
Cited by 12 | Viewed by 2835
Abstract
Most countries are facing problems of environmental pollution due to toxic organic pollutants being discharged into the environment from various man-made sources. Heterogeneous photocatalysis is a possible solution for the mentioned problem, and it has been widely applied for the removal of pollutants [...] Read more.
Most countries are facing problems of environmental pollution due to toxic organic pollutants being discharged into the environment from various man-made sources. Heterogeneous photocatalysis is a possible solution for the mentioned problem, and it has been widely applied for the removal of pollutants from aqueous solutions, thanks to its high removal efficiency and environmental friendliness. Among the commonly used metal oxides, ZnO has attracted researchers’ interests due to its ecofriendly and nontoxic nature. In this work, ZnO nanoparticles (ZnO-NPs) were prepared by the precipitation method from water (w) and ethanol solutions of the corresponding metal precursors (zinc–acetate dihydrate, A_ZnO, and zinc–nitrate hexahydrate, N_ZnO) followed by calcination at different temperatures. The structure and morphology of the prepared catalysts were characterized by different techniques (XRD, BET, and SEM). Based on the XRD results, it can be seen that the synthesized NPs possess high purity. Furthermore, at a higher calcination temperature, a higher crystal size was observed, which was more intense in the case of the ethanol solution of the precursors. The BET analysis showed macropores at the surface and also indicated that the increased temperature led to decreased surface area. Finally, SEM images showed that in the case of the water precursor solution, an irregular, rod-like shape of the NPs was observed. The photocatalytic properties of newly synthesized ZnO-NPs exposed to simulated sunlight were examined during the removal of pesticide clomazone (CLO) and the antidepressant drug amitriptyline (AMI). ZnO-NPs prepared by the precipitation method from the water solution of zinc–acetate dihydrate and calcined at 500 °C (A_ZnOw_500) showed the highest performance under simulated sunlight. Furthermore, the activity of A_ZnOw_500 and N_ZnOw_500 catalysts in the removal of three organic pollutants from water—two pesticides (sulcotrione (SUL) and CLO) and one pharmaceutical (AMI)—was also compared. Results showed that decreased photocatalytic activity was observed in the presence of N_ZnOw_500 NPs in all investigated systems. Finally, the effect of the initial pH was also examined. It was found that in the case of CLO and SUL, there was no influence of the initial pH, while in the case of AMI the kapp was slightly increased in the range from pH ~7 to pH ~10. Full article
(This article belongs to the Section Environmental Separations)
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23 pages, 6194 KB  
Article
Multidimensional Fractionation of Particles
by Uwe Frank, Jana Dienstbier, Florentin Tischer, Simon E. Wawra, Lukas Gromotka, Johannes Walter, Frauke Liers and Wolfgang Peukert
Separations 2023, 10(4), 252; https://doi.org/10.3390/separations10040252 - 13 Apr 2023
Cited by 3 | Viewed by 2568
Abstract
The increasing complexity in particle science and technology requires the ability to deal with multidimensional property distributions. We present the theoretical background for multidimensional fractionations by transferring the concepts known from one dimensional to higher dimensional separations. Particles in fluids are separated by [...] Read more.
The increasing complexity in particle science and technology requires the ability to deal with multidimensional property distributions. We present the theoretical background for multidimensional fractionations by transferring the concepts known from one dimensional to higher dimensional separations. Particles in fluids are separated by acting forces or velocities, which are commonly induces by external fields, e.g., gravitational, centrifugal or electro-magnetic fields. In addition, short-range force fields induced by particle interactions can be employed for fractionation. In this special case, nanoparticle chromatography is a recent example. The framework for handling and characterizing multidimensional separation processes acting on multidimensional particle size distributions is presented. Illustrative examples for technical realizations are given for shape-selective separation in a hydrocyclone and for density-selective separation in a disc separator. Full article
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17 pages, 1944 KB  
Article
Salting-Out Assisted Liquid-Liquid Extraction for UPLC-MS/MS Determination of Thyroxine and Steroid Hormones in Human Serum and Fish Plasma
by Alemnesh Yirda Urge, Daniela Maria Pampanin, Maria Elena Martino, David Lausten Knudsen and Cato Brede
Separations 2023, 10(4), 240; https://doi.org/10.3390/separations10040240 - 5 Apr 2023
Cited by 6 | Viewed by 5814
Abstract
Measuring the level of steroid and thyroxine hormones is key to understanding organism health conditions. Liquid chromatography coupled with tandem mass spectrometry has become the method of choice for such hormone analyses in clinical laboratories. Detection of hormones at low levels typically requires [...] Read more.
Measuring the level of steroid and thyroxine hormones is key to understanding organism health conditions. Liquid chromatography coupled with tandem mass spectrometry has become the method of choice for such hormone analyses in clinical laboratories. Detection of hormones at low levels typically requires a time-consuming sample preparation, such as liquid-liquid extraction followed by solvent evaporation and re-solubilization of the sample extract. Instead, we applied salting-out assisted liquid-liquid extraction (SALLE) for the extraction of thyroxine, testosterone, cortisone, and cortisol from human serum and fish plasma samples. SALLE allowed direct injection of sample extracts. Sodium chloride and ammonium sulfate were evaluated as salting-out reagents together with four different organic solvents. High extraction recovery and reduced matrix interference were achieved by using ammonium sulfate together with 10% methanol in acetonitrile. Limits of quantification were in the range of 0.1–0.2 ng/mL and signal responses were linear (R2 > 0.997) up to at least 100 ng/mL for all hormones. The method was applied for hormone measurements in fish plasma. In conclusion, SALLE combines the simplicity of crude protein precipitation with the high analyte enrichment of a liquid-liquid extraction. Here we have presented it as a novel sample preparation method for clinical laboratories where mass spectrometry is utilized in the field of endocrinology. Full article
(This article belongs to the Special Issue Mass Spectrometry Development and Its Application in Bioanalysis)
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18 pages, 5932 KB  
Article
Green-Engineered Barrier Creams with Montmorillonite-Chlorophyll Clays as Adsorbents for Benzene, Toluene, and Xylene
by Meichen Wang and Timothy D. Phillips
Separations 2023, 10(4), 237; https://doi.org/10.3390/separations10040237 - 4 Apr 2023
Cited by 11 | Viewed by 6066
Abstract
Dermal exposures to hazardous environmental chemicals in water can significantly affect the morphology and integrity of skin structure, leading to enhanced and deeper penetration. Organic solvents, such as benzene, toluene, and xylene (BTX), have been detected in humans following skin exposure. In this [...] Read more.
Dermal exposures to hazardous environmental chemicals in water can significantly affect the morphology and integrity of skin structure, leading to enhanced and deeper penetration. Organic solvents, such as benzene, toluene, and xylene (BTX), have been detected in humans following skin exposure. In this study, novel barrier cream formulations (EVBTM) engineered with either montmorillonite (CM and SM) or chlorophyll-amended montmorillonite (CMCH and SMCH) clays were tested for their binding efficacy for BTX mixtures in water. The physicochemical properties of all sorbents and barrier creams were characterized and were shown to be suitable for topical application. In vitro adsorption results indicated that EVB-SMCH was the most effective and favorable barrier for BTX, as supported by the high binding percentage (29–59% at 0.05 g and 0.1 g), stable binding at equilibrium, low desorption rates, and high binding affinity. Pseudo-second-order and the Freundlich models best fit the adsorption kinetics and isotherms, and the adsorption was an exothermic reaction. Ecotoxicological models using L. minor and H. vulgaris that were submersed in aqueous culture media showed that the inclusion of 0.05% and 0.2% EVB-SMCH reduced BTX concentration. This result was further supported by the significant and dose-dependent increase in multiple growth endpoints, including plant frond number, surface area, chlorophyll content, growth rate, inhibition rate, and hydra morphology. The in vitro adsorption results and in vivo plant and animal models indicated that green-engineered EVB-SMCH can be used as an effective barrier to bind BTX mixtures and interrupt their diffusion and dermal contact. Full article
(This article belongs to the Special Issue Applications of Porous Materials in Adsorption)
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24 pages, 6367 KB  
Review
Removal of Azo Dyes from Wastewater through Heterogeneous Photocatalysis and Supercritical Water Oxidation
by Vincenzo Vaiano and Iolanda De Marco
Separations 2023, 10(4), 230; https://doi.org/10.3390/separations10040230 - 27 Mar 2023
Cited by 64 | Viewed by 9937
Abstract
Azo dyes are synthetic organic dyes used in the textile, leather, and paper industries. They pose environmental problems due to their toxic and persistent nature. The toxicity is due to the presence of azo groups in the dye molecule that can break down [...] Read more.
Azo dyes are synthetic organic dyes used in the textile, leather, and paper industries. They pose environmental problems due to their toxic and persistent nature. The toxicity is due to the presence of azo groups in the dye molecule that can break down into aromatic amines, which are highly toxic to aquatic organisms and humans. Various treatment methods have been developed to remove azo dyes from wastewater. Conventional wastewater treatments have some drawbacks, such as high operating costs, long processing times, generation of sludge, and the formation of toxic by-products. For these reasons, a valid alternative is constituted by advanced oxidation processes. Good results have been obtained using heterogeneous photocatalysis and supercritical water oxidation. In the former method, a photocatalyst is in contact with wastewater, a suitable light activates the catalyst, and generated reactive oxygen species that react with pollutants through oxidative reactions to their complete mineralization; the latter involves pressurizing and heating wastewater to supercritical conditions in a reactor vessel, adding an oxidizing agent to the supercritical water, and allowing the mixture to react. In this review paper, works in the literature that deal with processing wastewater containing azo dyes through photocatalysts immobilized on macroscopic supports (structured photocatalysts) and the supercritical water oxidation technique have been critically analyzed. In particular, advancement in the formulation of structured photocatalysts for the degradation of azo dyes has been shown, underlying different important features, such as the type of support for the photoactive phase, reactor configuration, and photocatalytic efficiency in terms of dye degradation and photocatalyst stability. In the case of supercritical water oxidation, the main results regarding COD and TOC removal from wastewater containing azo dyes have been reported, taking into account the reactor type, operating pressure, and temperature, as well as the reaction time. Full article
(This article belongs to the Special Issue Development of Materials for Separation and Detection of Metals and Chemicals)
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15 pages, 1865 KB  
Article
Development and Validation of a Confirmatory Method for the Determination of 12 Coccidiostat Residues in Eggs and Muscle by Means of Liquid Chromatography Coupled to Hybrid High Resolution Mass Spectrometry
by Federica Castellani, Matteo Ricci, Maria Novella Colagrande, Giampiero Scortichini and Giorgio Saluti
Separations 2023, 10(3), 202; https://doi.org/10.3390/separations10030202 - 14 Mar 2023
Cited by 7 | Viewed by 2983
Abstract
A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) [...] Read more.
A confirmatory, highly selective multi-residue method based on liquid chromatography coupled to hybrid high resolution mass spectrometry (LC-Q-Orbitrap) was developed and validated for the determination of 12 regulated coccidiostats in eggs and muscle. Particularly, ionophore antibiotics (lasalocid, maduramicin, monensin, narasin, salinomycin and semduramicin) and synthetic coccidiostats (diclazuril, halofuginone, nicarbazin as 4,4′-dinitrocarbanilide fraction, robenidine and toltrazuril as toltrazuril-sulphone) were included in the method. The sample preparation consisted in the extraction of the analytes from the matrix with acetonitrile, followed by a clean-up step with Oasis® PRiME HLB SPE and a defatting procedure with n-hexane. Validation was successfully performed according to Commission Implementing Regulation (EU) 2021/808, starting from 1 µg kg−1. The procedure was verified through the analysis of a certified reference material (CRM) and the occurrence of the residues was assessed in the context of the Italian National Residue Control Plan (NRCP). Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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32 pages, 3193 KB  
Review
Application of Hydrogen-Bonded Organic Frameworks in Environmental Remediation: Recent Advances and Future Trends
by Yu Zhang, Mengfei Tian, Zahid Majeed, Yuxin Xie, Kaili Zheng, Zidan Luo, Chunying Li and Chunjian Zhao
Separations 2023, 10(3), 196; https://doi.org/10.3390/separations10030196 - 13 Mar 2023
Cited by 21 | Viewed by 6686
Abstract
The hydrogen-bonded organic frameworks (HOFs) are a class of porous materials with crystalline frame structures, which are self-assembled from organic structures by hydrogen bonding in non-covalent bonds π-π packing and van der Waals force interaction. HOFs are widely used in environmental remediation due [...] Read more.
The hydrogen-bonded organic frameworks (HOFs) are a class of porous materials with crystalline frame structures, which are self-assembled from organic structures by hydrogen bonding in non-covalent bonds π-π packing and van der Waals force interaction. HOFs are widely used in environmental remediation due to their high specific surface area, ordered pore structure, pore modifiability, and post-synthesis adjustability of various physical and chemical forms. This work summarizes some rules for constructing stable HOFs and the synthesis of HOF-based materials (synthesis of HOFs, metallized HOFs, and HOF-derived materials). In addition, the applications of HOF-based materials in the field of environmental remediation are introduced, including adsorption and separation (NH3, CO2/CH4 and CO2/N2, C2H2/C2He and CeH6, C2H2/CO2, Xe/Kr, etc.), heavy metal and radioactive metal adsorption, organic dye and pesticide adsorption, energy conversion (producing H2 and CO2 reduced to CO), organic dye degradation and pollutant sensing (metal ion, aniline, antibiotic, explosive steam, etc.). Finally, the current challenges and further studies of HOFs (such as functional modification, molecular simulation, application extension as remediation of contaminated soil, and cost assessment) are discussed. It is hoped that this work will help develop widespread applications for HOFs in removing a variety of pollutants from the environment. Full article
(This article belongs to the Special Issue Applications of Porous Materials in Adsorption)
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18 pages, 4876 KB  
Article
Deep Eutectic Solvent-Based Microwave-Assisted Extraction for the Extraction of Seven Main Flavonoids from Ribes mandshuricum (Maxim.) Kom. Leaves
by Wei Wang, Si-Qiu Xiao, Ling-Yu Li and Qing-Yan Gai
Separations 2023, 10(3), 191; https://doi.org/10.3390/separations10030191 - 10 Mar 2023
Cited by 13 | Viewed by 4471
Abstract
Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from [...] Read more.
Flavonoids exhibit many biological properties, so it is very important to find an efficient and green method to extract them from plant materials. In this paper, DES-MAE (deep eutectic solvent-based microwave-assisted extraction) technique was developed to extract the seven major active flavonoids from Ribes mandshuricum leaves, namely, trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol. After the completion of the extraction process, macroporous adsorption resin was used for the purification of seven flavonoids. The BBD (Box–Behnken design) method combined with RSM (response surface methodology) was applied to acquire the optimal operating conditions of DES-MAE. The optimal parameters were: temperature: 54 °C, time: 10 min, extraction solvent: choline chloride/lactic acid with a 1:2 mass ratio, water content: 25%, and liquid/solid ratio: 27 mL/g. The yields of the seven target flavonoids were 4.78, 2.57, 1.25, 1.15, 0.34, 0.32, and 0.093 mg/g DW (dry weight), respectively. The direct purification of trifolin, isoquercetin, rutin, astragalin, quercetin, hyperoside, and kaempferol in DES-MAE solution was achieved by using macroporous resin X-5. The recoveries were 87.02%, 81.37%, 79.64%, 87.13%, 97.36%, 88.08%, and 99.39%, respectively. The results showed that DES-MAE followed by MRCC (macroporous resin column chromatography) represents a promising approach to extracting and separating active components from plants. Full article
(This article belongs to the Special Issue Novel Approach for Natural Product Separation from Plants)
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15 pages, 7415 KB  
Review
Steric Exclusion Chromatography for Purification of Biomolecules—A Review
by Jennifer J. Labisch, G. Philip Wiese and Karl Pflanz
Separations 2023, 10(3), 183; https://doi.org/10.3390/separations10030183 - 8 Mar 2023
Cited by 7 | Viewed by 5743
Abstract
Steric exclusion chromatography (SXC) is a purification method that is based on steric exclusion effects from the surface of the target and a hydrophilic stationary phase after the addition of polyethylene glycol (PEG), which leads to an association of the target with the [...] Read more.
Steric exclusion chromatography (SXC) is a purification method that is based on steric exclusion effects from the surface of the target and a hydrophilic stationary phase after the addition of polyethylene glycol (PEG), which leads to an association of the target with the stationary phase without direct binding, such as covalent, electrostatic, and hydrophilic/hydrophobic interactions. The gentle nature of the method has led to an increased focus on sensitive targets such as enveloped viruses with potential for other sensitive entities, e.g., extracellular vesicles and virus-like particles. SXC is related to PEG-mediated protein precipitation, but investigation of further process parameters was crucial to gain a better understanding of the SXC method. After explaining mechanistic fundamentals and their discovery, this review summarizes the findings on SXC from its first reference 11 years ago until today. Different applications of SXC are presented, demonstrating that the method can be used for a wide variety of targets and achieves high recovery rates and impurity removal. Further, critical process parameters for successful process implementation are discussed, including technical requirements, buffer composition, and scalability. Full article
(This article belongs to the Special Issue Advances in Separation Engineering)
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17 pages, 2117 KB  
Article
Experimental Design and Multiple Response Optimization for the Extraction and Quantitation of Thirty-Four Priority Organic Micropollutants in Tomatoes through the QuEChERS Approach
by Luca Rivoira, Massimo Del Bubba, Giasmin Cecconi, Michele Castiglioni, Valentina Testa, Mattia Isola and Maria Concetta Bruzzoniti
Separations 2023, 10(3), 174; https://doi.org/10.3390/separations10030174 - 6 Mar 2023
Cited by 3 | Viewed by 2829
Abstract
The chemical contamination in fruit and vegetables represents a challenging analytical issue, with tomatoes deserving to be investigated as they are fundamental components of the Mediterranean diet. Polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs contamination is of serious concern, due to [...] Read more.
The chemical contamination in fruit and vegetables represents a challenging analytical issue, with tomatoes deserving to be investigated as they are fundamental components of the Mediterranean diet. Polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs contamination is of serious concern, due to particulate deposition and to uptake from contaminated soils and water. However, time-consuming, non-simultaneous and/or non-eco-friendly extraction procedures are typically used to investigate organic contamination in tomatoes, with nitro-PAHs that have not yet been studied. Based on these premises, this work reports the development of a QuEChERS-based approach, coupled with gas chromatography/mass spectrometry, for the simultaneous determination of 16 PAHs, 14 PCBs and 4 nitro-PAHs in three tomato cultivars. The effect of dichloromethane, cyclohexane and acetone, as well as of four clean-up phases were studied through the advanced combination of full factorial experimental design and multiple response optimization approaches. The final protocol, based on cyclohexane extraction followed by a double purification step with primary secondary amine and octadecyl silica and a sulfuric acid oxidation, led to 60–120% recoveries (RSD% < 15%). Good repeatability (inter-day precision <15%) and negligible matrix effect (<16%) were confirmed and the protocol was applied to the analysis of real tomato samples purchased in a local market. Full article
(This article belongs to the Section Environmental Separations)
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17 pages, 2273 KB  
Article
Characterization of the Aroma Profile of Food Smoke at Controllable Pyrolysis Temperatures
by Marina Rigling, Laura Höckmeier, Malte Leible, Kurt Herrmann, Monika Gibis, Jochen Weiss and Yanyan Zhang
Separations 2023, 10(3), 176; https://doi.org/10.3390/separations10030176 - 6 Mar 2023
Cited by 12 | Viewed by 4205
Abstract
Smoking is used to give food its typical aroma and to obtain the desired techno-functional properties of the product. To gain a deeper knowledge of the whole process of food smoking, a controllable smoking process was developed, and the influence of wood pyrolysis [...] Read more.
Smoking is used to give food its typical aroma and to obtain the desired techno-functional properties of the product. To gain a deeper knowledge of the whole process of food smoking, a controllable smoking process was developed, and the influence of wood pyrolysis temperature (150–900 °C) on the volatile compounds in the smoking chamber atmosphere was investigated. The aroma profile of smoke was decoded by headspace solid-phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS). Subsequently, the correlations in the most important substance classes, as well as in individual target components, were investigated by the Pearson test. Phenols and lactones showed an increase over the entire applied temperature range (rT = 0.94 and rT = 0.90), whereas furans and carbonyls showed no strict temperature dependence (rT < 0.6). Investigations on single aroma compounds showed that not all compounds of one substance class showed the same behavior, e.g., guaiacol showed no significant increase over the applied pyrolysis temperature, whereas syringol and hydoxyacetone showed a plateau after 450 °C, and phenol and cyclotene increased linear over the applied temperature range. These findings will help to better understand the production of aroma-active compounds during smoke generation in order to meet consumers preferences. Full article
(This article belongs to the Special Issue Application of Chromatography in Analytical Chemistry)
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15 pages, 2820 KB  
Article
Effect of Surfactants on Reverse Osmosis Membrane Performance
by Aymen Halleb, Mitsutoshi Nakajima, Fumio Yokoyama and Marcos Antonio Neves
Separations 2023, 10(3), 168; https://doi.org/10.3390/separations10030168 - 2 Mar 2023
Cited by 8 | Viewed by 4824
Abstract
The aim of this study was to evaluate the performance of a reverse osmosis (RO) membrane in surfactant removal using various surfactant model aqueous solutions. The separation tests were performed with laboratory scale units in a dead-end configuration. Cellulose Acetate (CA) and Polyamide [...] Read more.
The aim of this study was to evaluate the performance of a reverse osmosis (RO) membrane in surfactant removal using various surfactant model aqueous solutions. The separation tests were performed with laboratory scale units in a dead-end configuration. Cellulose Acetate (CA) and Polyamide (PA) RO membranes were used with nonionic, anionic, or cationic surfactants at a wide range of concentrations. Membrane performance was evaluated using permeate flux and total organic carbon (TOC) rejection. The effects of surfactant type and concentration on RO membranes were assessed. Permeate flux of the PA membrane depended on the surfactant type and concentration. The separation of cationic surfactant aqueous solutions yielded the lowest permeate flux, followed by nonionic and anionic surfactant aqueous solutions, respectively. Surfactant adsorption on the membrane surface occurred at very low concentration of cationic and nonionic surfactants due to electrostatic and hydrophobic interactions, respectively, which affected permeate flux, and micelles did not affect the permeate flux of PA membrane. However, for CA membrane the permeate flux was not affected by the feed solution. Both membranes exhibited satisfactory TOC rejection (92–99%). This study highlights the importance of assessing interactions between membrane material and surfactant molecules to mitigate membrane fouling and guarantee a better performance of the RO membrane. Full article
(This article belongs to the Special Issue Separation Technologies in Water and Wastewater Treatment and Resources Recovery)
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19 pages, 4976 KB  
Article
Determination of 27 Glucocorticoids in Urine by Ultra-High-Performance Liquid Chromatography-Tandem Mass Spectrometry Using UniSprayTM Source
by Mariola Wicka, Krzysztof Grucza, Aleksandra Drapała, Patryk Konarski and Dorota Kwiatkowska
Separations 2023, 10(3), 155; https://doi.org/10.3390/separations10030155 - 24 Feb 2023
Cited by 1 | Viewed by 2852
Abstract
Glucocorticoids (GCs) are a group of the most important and commonly used anti-inflammatory, antiallergenic, and immunosuppressive drugs. Like narcotics, they can be addictive if taken at increasing doses to achieve greater analgesic effects. The purpose of the study was to develop initial and [...] Read more.
Glucocorticoids (GCs) are a group of the most important and commonly used anti-inflammatory, antiallergenic, and immunosuppressive drugs. Like narcotics, they can be addictive if taken at increasing doses to achieve greater analgesic effects. The purpose of the study was to develop initial and confirmation testing analytical methods that would allow for the identification of glucocorticoid class substances in human urine to be used for routine analyses for the purposes of prosecution in the case of abuse, for clinical toxicology, medical jurisprudence, as well as for routine testing of athletes for the presence of prohibited substances in sports by means of ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) using a new generation ionization source UniSprayTM (U.S). This new method allows for the simultaneous detection of 27 glucocorticoids in human urine using LC-MS/MS. The tests conducted yielded relatively low LOD and LOQ values, ranging from 0.06 ng/mL to 0.14 ng/mL and 0.75 ng/mL for LOD and LOQ, respectively. Full article
(This article belongs to the Topic Application of Analytical Chemistry in Exercise Physiology and Pharmacology)
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16 pages, 821 KB  
Review
Solid Phase Microextraction—A Promising Tool for Graft Quality Monitoring in Solid Organ Transplantation
by Kamil Łuczykowski, Natalia Warmuzińska and Barbara Bojko
Separations 2023, 10(3), 153; https://doi.org/10.3390/separations10030153 - 23 Feb 2023
Cited by 3 | Viewed by 1959
Abstract
Solid organ transplantation is a life-saving intervention for patients suffering from end-stage organ failure. Although improvements in surgical techniques, standards of care, and immunosuppression have been observed over the last few decades, transplant centers have to face the problem of an insufficient number [...] Read more.
Solid organ transplantation is a life-saving intervention for patients suffering from end-stage organ failure. Although improvements in surgical techniques, standards of care, and immunosuppression have been observed over the last few decades, transplant centers have to face the problem of an insufficient number of organs for transplantation concerning the growing demand. An opportunity to increase the pool of organs intended for transplantation is the more frequent use of organs from extended criteria and the development of analytical methods allowing for a better assessment of the quality of organs to minimize the risk of post-transplant organ injury and rejection. Therefore, solid-phase microextraction (SPME) has been proposed in various studies as an effective tool for determining compounds of significance during graft function assessment or for the chemical profiling of grafts undergoing various preservation protocols. This review summarizes how SPME addresses the analytical challenges associated with different matrices utilized in the peri-transplant period and discusses its potential as a diagnostic tool in future work. Full article
(This article belongs to the Special Issue Women in Separations)
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27 pages, 1161 KB  
Review
Renewable Resource Biosorbents for Pollutant Removal from Aqueous Effluents in Column Mode
by Lavinia Tofan and Daniela Suteu
Separations 2023, 10(2), 143; https://doi.org/10.3390/separations10020143 - 19 Feb 2023
Cited by 13 | Viewed by 5075
Abstract
The present work deals with the continuous flow systems based on renewable resource biosorbents towards the green removal of various categories of chemical pollutants from aqueous media. The opening discussions are focused on: (a) renewable resources; (b) biosorbents based on renewable resources; (c) [...] Read more.
The present work deals with the continuous flow systems based on renewable resource biosorbents towards the green removal of various categories of chemical pollutants from aqueous media. The opening discussions are focused on: (a) renewable resources; (b) biosorbents based on renewable resources; (c) dynamic biosorption. After these, the renewable resources biosorbents are reviewed according to the parameters of breakthrough curves. Subsequently, the targeted biosorbents are systematized and analyzed according to the following criteria: (a) their ability to work as remediation agents for heavy metal ions and dyes, respectively; (b) their relevancy for continuous biosorption processes applied both to synthetic aqueous solutions and real wastewaters. The perspective directions of research for the implementation of biosorbents from renewable resources in practical column strategies for wastewater treatment are recommended. Full article
(This article belongs to the Special Issue Removal of Emerging Pollutants and Environmental Analysis)
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16 pages, 1094 KB  
Review
Condensed Phase Membrane Introduction Mass Spectrometry: A Direct Alternative to Fully Exploit the Mass Spectrometry Potential in Environmental Sample Analysis
by Veronica Termopoli, Maurizio Piergiovanni, Davide Ballabio, Viviana Consonni, Emmanuel Cruz Muñoz and Fabio Gosetti
Separations 2023, 10(2), 139; https://doi.org/10.3390/separations10020139 - 17 Feb 2023
Cited by 7 | Viewed by 3663
Abstract
Membrane introduction mass spectrometry (MIMS) is a direct mass spectrometry technique used to monitor online chemical systems or quickly quantify trace levels of different groups of compounds in complex matrices without extensive sample preparation steps and chromatographic separation. MIMS utilizes a thin, semi-permeable, [...] Read more.
Membrane introduction mass spectrometry (MIMS) is a direct mass spectrometry technique used to monitor online chemical systems or quickly quantify trace levels of different groups of compounds in complex matrices without extensive sample preparation steps and chromatographic separation. MIMS utilizes a thin, semi-permeable, and selective membrane that directly connects the sample and the mass spectrometer. The analytes in the sample are pre-concentrated by the membrane depending on their physicochemical properties and directly transferred, using different acceptor phases (gas, liquid or vacuum) to the mass spectrometer. Condensed phase (CP) MIMS use a liquid as a medium, extending the range to new applications to less-volatile compounds that are challenging or unsuitable to gas-phase MIMS. It directly allows the rapid quantification of selected compounds in complex matrices, the online monitoring of chemical reactions (in real-time), as well as in situ measurements. CP-MIMS has expanded beyond the measurement of several organic compounds because of the use of different types of liquid acceptor phases, geometries, dimensions, and mass spectrometers. This review surveys advancements of CP-MIMS and its applications to several molecules and matrices over the past 15 years. Full article
(This article belongs to the Section Environmental Separations)
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26 pages, 1814 KB  
Review
Potential of Advanced Oxidation as Pretreatment for Microplastics Biodegradation
by Kristina Bule Možar, Martina Miloloža, Viktorija Martinjak, Matija Cvetnić, Hrvoje Kušić, Tomislav Bolanča, Dajana Kučić Grgić and Šime Ukić
Separations 2023, 10(2), 132; https://doi.org/10.3390/separations10020132 - 15 Feb 2023
Cited by 36 | Viewed by 8867
Abstract
In the last two decades, microplastics (MP) have been identified as an emerging environmental pollutant. Due to their small size, MP particles may easily enter the food chain, where they can have adverse effects on organisms and the environment in general. The common [...] Read more.
In the last two decades, microplastics (MP) have been identified as an emerging environmental pollutant. Due to their small size, MP particles may easily enter the food chain, where they can have adverse effects on organisms and the environment in general. The common methods for the removal of pollutants from the environment are not fully effective in the elimination of MP; thus, it is necessary to find a more suitable treatment method(s). Among the various approaches tested, biodegradation is by far the most environmentally friendly and economically acceptable remediation approach. However, it has serious drawbacks, generally related to the rather low removal rate and often insufficient efficiency. Therefore, it would be beneficial to use some of the less economical but more efficient methods as pretreatment prior to biodegradation. Such pretreatment would primarily serve to increase the roughness and hydrophilicity of the surface of MP, making it more susceptible to bioassimilation. This review focuses on advanced oxidation processes (AOPs) as treatment methods that can enhance the biodegradation of MP particles. It considers MP particles of the six most commonly used plastic polymers, namely: polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate and polyurethane. The review highlights organisms with a high potential for biodegradation of selected MP particles and presents the potential benefits that AOP pretreatment can provide for MP biodegradation. Full article
(This article belongs to the Special Issue Separation and Analysis of Micro- and Nanoplastics in the Environment)
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15 pages, 1700 KB  
Article
Effect of Extraction Methods on Essential Oil Composition: A Case Study of Irish Bog Myrtle-Myrica gale L.
by Shipra Nagar, Maria Pigott, Sophie Whyms, Apolline Berlemont and Helen Sheridan
Separations 2023, 10(2), 128; https://doi.org/10.3390/separations10020128 - 14 Feb 2023
Cited by 5 | Viewed by 5564
Abstract
Myrica gale is an aromatic peatland shrub that has reported traditional use as an insect repellent. Different extraction methodologies were used in this study to isolate the essential oil of Myrica gale L., including Clevenger hydrodistillation (CH) and microwave-assisted hydrodistillation (MAH). The oils, [...] Read more.
Myrica gale is an aromatic peatland shrub that has reported traditional use as an insect repellent. Different extraction methodologies were used in this study to isolate the essential oil of Myrica gale L., including Clevenger hydrodistillation (CH) and microwave-assisted hydrodistillation (MAH). The oils, isolated from different plant parts (leaves, fruit and branches) collected in summer and autumn, were analysed by GC-MS and the volatiles from plant tissue were directly analysed by headspace-GC-MS. A total of 58 components were identified, including 15 monoterpene hydrocarbons (22.78–98.98%), 14 oxygenated monoterpenes (0.91–43.02%), 13 sesquiterpene hydrocarbons (0.05–24.98%), 3 oxygenated sesquiterpenes (0.07–13.16%) and 13 other compounds (0.05–5.21%). Headspace sampling furnished monoterpenes, while CH and MAH extracted monoterpenes and sesquiterpenes, with α-pinene (6.04–70.45%), eucalyptol (0.61–33.80%), limonene (2.27–20.73%) and α-phellandrene (2.33–15.61%) as major components in all plant parts. Quantitative differences occurred between extraction methodologies, with MAH yielding higher quantities of monoterpene and sesquiterpene hydrocarbons and CH targeting oxygenated counterparts. Leaves gave more complex chemical fingerprints than branches and fruit, and the summer collection yielded more components than the autumn collections. An OPLS-DA model was applied to the GC-MS data to compare the chemical profiles based on the extraction techniques and plant parts, and molecular networks were obtained for monoterpenes and sesquiterpenes connected via biosynthetic pathways. The essential oil profile of Myrica gale was influenced by the season of collection, plant part and extraction method. Full article
(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)
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15 pages, 5263 KB  
Article
Preparation of Fe3O4-Reduced Graphene-Activated Carbon from Wastepaper in the Dispersive Solid-Phase Extraction and UHPLC-PDA Determination of Antibiotics in Human Plasma
by Pantaleone Bruni, Pasquale Avino, Vincenzo Ferrone, Serena Pilato, Nadia Barbacane, Valentino Canale, Giuseppe Carlucci and Stefania Ferrari
Separations 2023, 10(2), 115; https://doi.org/10.3390/separations10020115 - 7 Feb 2023
Cited by 5 | Viewed by 2393
Abstract
In this work, a sorbent was prepared from wastepaper samples enriched with iron oxide particles and graphene oxide and used in the solid phase extraction of antibiotics. The precursor underwent a carbothermal reduction to promote the formation of paramagnetic phases useful for the [...] Read more.
In this work, a sorbent was prepared from wastepaper samples enriched with iron oxide particles and graphene oxide and used in the solid phase extraction of antibiotics. The precursor underwent a carbothermal reduction to promote the formation of paramagnetic phases useful for the recovery of the sorbent during the analysis, and to disperse and fix graphene and the iron oxide in a durable way throughout the cellulose structure. Characterizations were carried out to evaluate the composition (Raman, XRD and EDX) and the morphological structure (SEM) of the material. A UHPLC-PDA method was developed for the simultaneous determination of antibiotics from different drug families (carbapenems, fluoroquinolones, β-lactams) using a 120 SB-C 18 poroshell column (50 × 2.1 mm I.D., 2.7 um particle size) and a mobile phase consisting of 10 mM acetate buffer at pH 5 (Line A) and acetonitrile (Line B) both containing 0.1% of triethylamine. A gradient elution was used for the separation of the analytes, while for the quantitative analysis each analyte was determined at its maximum wavelength. Several experiments were carried out to evaluate the influence of different parameters involving the dispersive magnetic solid phase extraction of these analytes. Samples were extracted using 25 mg of sorbent at pH 5 and desorbed in 5 min using methanol. We report herein on some of the outstanding advantages of using carbon-based sorbent, such as lower toxicity, scalability, improved absorption capacity, target selectivity and stability in acidic medium. Moreover, from the results obtained it is evident that, despite the use of some recycled materials, the performances obtained were comparable or even superior to the methods reported in the literature. Full article
(This article belongs to the Special Issue Recent Advances in Microextraction Technology for Analytical Sample Preparation)
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15 pages, 1210 KB  
Article
Investigation of Imidazolium-Based Ionic Liquids as Additives for the Separation of Urinary Biogenic Amines via Capillary Electrophoresis
by Natalia Kaczmarczyk, Natalia Treder, Piotr Kowalski, Alina Plenis, Anna Roszkowska, Tomasz Bączek and Ilona Olędzka
Separations 2023, 10(2), 116; https://doi.org/10.3390/separations10020116 - 7 Feb 2023
Cited by 3 | Viewed by 2146
Abstract
Ionic liquids (ILs), such as imidazoles, can be used to prevent the sorption of analytes onto the walls of the capillary. Prior works have confirmed that coating the capillary wall with a cationic layer can increase its surface stability, thereby improving the repeatability [...] Read more.
Ionic liquids (ILs), such as imidazoles, can be used to prevent the sorption of analytes onto the walls of the capillary. Prior works have confirmed that coating the capillary wall with a cationic layer can increase its surface stability, thereby improving the repeatability of the separation process. In this study, micellar electrokinetic chromatography (MEKC) is employed to evaluate how two ILs with different anions—namely, 1-hexyl-3-methylimidazolium chloride [HMIM+Cl−] and 1-hexyl-3-methylimidazolium tetrafluoroborate [HMIM+BF4−]—affect the separation efficiency for biogenic amines (BAs) such as metanephrine (M), normetanephrine (NM), vanilmandelic acid (VMA), and homovanillic acid (HVA) in urine samples. To this end, solid-phase extraction (SPE) is employed using different sample pH values, with the results demonstrating that HVA and VMA is easily extracted at a sample pH of 5.5, while a sample pH of 9.0 facilitated the extraction of M and NM. In the applied SPE protocol, selected analytes were isolated from urine samples using hydrophilic–lipophilic-balanced (HLB) columns and eluted with methanol (MeOH). The validation data confirmed the method’s linearity (R2 > 0.996) for all analytes within the range of 0.25–10 µg/mL. The applicability of the optimized SPE-MEKC-UV method was confirmed by employing it to quantify clinically relevant BAs in real urine samples from pediatric neuroblastoma (NBL) patients. Full article
(This article belongs to the Special Issue Ionic Liquids in Separation Technology)
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45 pages, 3584 KB  
Review
The State of Critical and Strategic Metals Recovery and the Role of Nuclear Techniques in the Separation Technologies Development: Review
by Nelson R. Kiprono, Tomasz Smolinski, Marcin Rogowski and Andrzej G. Chmielewski
Separations 2023, 10(2), 112; https://doi.org/10.3390/separations10020112 - 5 Feb 2023
Cited by 13 | Viewed by 4930
Abstract
The extraction of useful minerals or geological materials from the Earth’s crust, most typically from various sources, is crucial to a country’s development and progress. Mineral-rich countries use these resources to transform their economies and propel them toward long-term prosperity. There is an [...] Read more.
The extraction of useful minerals or geological materials from the Earth’s crust, most typically from various sources, is crucial to a country’s development and progress. Mineral-rich countries use these resources to transform their economies and propel them toward long-term prosperity. There is an urgent need for the world to increase mineral exploration efforts, improve the recycling of important metal-containing resources, and extract them using upgraded hydrometallurgical procedures with high recovery efficiency. This review paper highlights the importance of strategic and critical metals in the economy and the role of nuclear techniques in the analysis, process optimization, and remediation of metals using solvent extraction, adsorption, and chromatographic resins. Radiotracer analysis, X-Ray Fluorescence spectrometry (XRF), Neutron Activation Analysis (NAA), and X-Ray Diffraction (XRD) are appropriate for improving laboratory-based hydrometallurgical processes, with future technical and economic benefits. The development and installation of novel instruments to provide the real-time control of mining and mineral processing plants for improved control have the potential to aid in the recovery of a broad range of metals. Full article
(This article belongs to the Special Issue Recent Advances in Metal Separations and Recovery)
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28 pages, 2055 KB  
Review
Identification and Isolation Techniques for Plant Growth Inhibitors in Rice
by Nguyen Thi Hai Anh, La Hoang Anh, Nguyen Phuong Mai, Nguyen Van Quan and Tran Dang Xuan
Separations 2023, 10(2), 105; https://doi.org/10.3390/separations10020105 - 3 Feb 2023
Cited by 5 | Viewed by 4804
Abstract
Plant growth inhibitors (PGIs) in rice (Oryza sativa), or rice allelochemicals, are secondary metabolites that are either exudated by rice plants to cope with natural competitors or produced during the decomposition of rice by-products in the paddy fields. Of these, the [...] Read more.
Plant growth inhibitors (PGIs) in rice (Oryza sativa), or rice allelochemicals, are secondary metabolites that are either exudated by rice plants to cope with natural competitors or produced during the decomposition of rice by-products in the paddy fields. Of these, the major groups of rice PGIs include phenolics, flavonoids, terpenoids, alkaloids, steroids, and fatty acids, which also exhibit potential medicinal and pharmaceutical properties. Recently, the exploitation of rice PGIs has attracted considerable attention from scientists worldwide. The biosynthesis, exudation, and release of PGIs are dependent on environmental conditions, relevant gene expression, and biodiversity among rice varieties. Along with the mechanism clarification, numerous analytical methods have been improved to effectively support the identification and isolation of rice PGIs during the last few decades. This paper provides an overview of rice PGIs and techniques used for determining and extracting those compounds from rice. In particular, the features, advantages, and limitations of conventional and upgraded extraction methods are comprehensively reported and discussed. The conventional extraction methods have been gradually replaced by advanced techniques consisting of pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), and solid-phase extraction (SPE). Meanwhile, thin-layer chromatography (TLC), liquid chromatography (LC), gas chromatography (GC), mass spectrometry (MS), nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS), infrared spectroscopy (IR), near-infrared spectroscopy (NIRS), and X-ray crystallography are major tools for rice PGI identification and confirmation. With smart agriculture becoming more prevalent, the statistics of rice PGIs and extraction methods will help to provide useful datasets for building an autonomous model for safer weed control. Conceivably, the efficient exploitation of rice PGIs will not only help to increase the yield and economic value of rice but may also pave the way for research directions on the development of smart and sustainable rice farming methods. Full article
(This article belongs to the Special Issue Separation, Extraction and Purification of Natural Products)
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19 pages, 3792 KB  
Article
Screening the Efficacy of a Microbial Consortium of Bacteria and Fungi Isolated from Different Environmental Samples for the Degradation of LDPE/TPS Films
by Dajana Kučić Grgić, Martina Miloloža, Vesna Ocelić Bulatović, Šime Ukić, Miroslav Slouf and Veronika Gajdosova
Separations 2023, 10(2), 79; https://doi.org/10.3390/separations10020079 - 24 Jan 2023
Cited by 15 | Viewed by 5309
Abstract
In this study, a screening of the efficacy of a microbial consortium of bacteria and fungi isolated from activated sludge, river sediment, and compost for the degradation of LDPE/TPS was performed. According to the morphological and biochemical characterization, eight bacteria, Bacillus sonorensis, [...] Read more.
In this study, a screening of the efficacy of a microbial consortium of bacteria and fungi isolated from activated sludge, river sediment, and compost for the degradation of LDPE/TPS was performed. According to the morphological and biochemical characterization, eight bacteria, Bacillus sonorensis, Bacillus subtilis, Lysinibacillus massiliensis, Bacillus licheniformis, Bacillus indicus, Bacillus megaterium, Bacillus cereus, and Pseudomonas alcaligenes, five molds, Aspergillus sp. 1, Aspergillus sp. 2, Trichoderma sp., Rhizopus sp., Penicillium sp., and Alternaria sp., and a yeast, Candida parapsilosis, were identified. The first experiment E1 was inoculated with microorganisms isolated from activated sludge and river sediment, and E2 with microorganisms isolated from compost. In both experiments, different types of polymeric materials, low density polyethylene (E1-1 and E2-1), thermoplastic starch (E1-2 and E2-2), low density polyethylene + thermoplastic starch (E1-3 and E2-3), low density polyethylene + thermoplastic starch + styrene-ethylene-styrene (E1-4 and E2-4) were added. The obtained results, weight loss, SEM, and FTIR analysis showed that the microorganisms in both experiments were able to degrade polymeric materials. The mixed culture of microorganisms in experiments E1-2 and E2-2 completely degraded TPS (thermoplastic starch). The percent weight losses of LDPE, LDPE+20% TPS, and LDPE+20% TPS+SEBS in experiment E1 were 3.3184%, 14.1152%, and 16.0062% and in experiment E2 were 3.9625%, 20.4520% and 21.9277%, respectively. SEM microscopy shows that the samples with a LDPE matrix exhibited moderate surface degradation and negligible oxidative degradation under the given conditions. FTIR/ATR data demonstrate that degradation was more intense in E2 than in E1. Full article
(This article belongs to the Section Environmental Separations)
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37 pages, 1502 KB  
Review
Factors Influencing the Prediction Accuracy of Model Peptides in Reversed-Phase Liquid Chromatography
by Othman Al Musaimi, Oscar M. Mercado-Valenzo and Daryl R. Williams
Separations 2023, 10(2), 81; https://doi.org/10.3390/separations10020081 - 24 Jan 2023
Cited by 6 | Viewed by 4037
Abstract
Hydrophobicity is an important physicochemical property of peptides in solution. As well as being strongly associated with peptide stability and aggregation, hydrophobicity governs the solution based chromatographic separation processes, specifically reversed-phase liquid chromatography (RPLC). In addition, hydrophobicity is a major physicochemical property of [...] Read more.
Hydrophobicity is an important physicochemical property of peptides in solution. As well as being strongly associated with peptide stability and aggregation, hydrophobicity governs the solution based chromatographic separation processes, specifically reversed-phase liquid chromatography (RPLC). In addition, hydrophobicity is a major physicochemical property of peptides in comparison to H-bonding, electrostatic, and aromatic properties in intermolecular interactions. However, a wide range of molecular factors can influence peptide hydrophobicity, with accurate predictions depending on specific peptide amino acid compositions, structure, and conformation. It is noticeable that peptide composition, the position of the amino acid, and its neighbouring groups play a crucial role in the elution process. In light of this, the same amino acid behaved differently depending on its position and neighbouring amino acid in the peptide chain. Extra attention should be paid to the denaturation process during the course of elution, as it has been shown to complicate and alter the elution pattern. This paper reports on the key peptide properties that can alter hydrophobicity and, consequently, the RPLC elution behaviour of the peptides, and it will conclude by proposing improved prediction algorithms for peptide elution in RPLC. Full article
(This article belongs to the Special Issue Advances in Chromatographic Analysis of Bioactive Compounds)
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16 pages, 4682 KB  
Article
Dimethyl Carbonate as a Mobile-Phase Modifier for Normal-Phase and Hydrophilic Interaction Liquid Chromatography
by Philip D. Boes, Sophie R. Elleman and Neil D. Danielson
Separations 2023, 10(2), 70; https://doi.org/10.3390/separations10020070 - 18 Jan 2023
Cited by 15 | Viewed by 5477
Abstract
We studied the use of dimethyl carbonate (DMC) as a non-toxic, aprotic modifier for hydrophilic liquid interaction chromatography (HILIC) and as a modifier for normal-phase liquid chromatography (LC). A comparison of ethyl acetate (EA) and DMC as organic mobile-phase modifiers in hexane for [...] Read more.
We studied the use of dimethyl carbonate (DMC) as a non-toxic, aprotic modifier for hydrophilic liquid interaction chromatography (HILIC) and as a modifier for normal-phase liquid chromatography (LC). A comparison of ethyl acetate (EA) and DMC as organic mobile-phase modifiers in hexane for normal-phase LC of phthalates was conducted with a silica column and showed that retention factors (k) at the same modifier percentage were about a factor of two greater for DMC. Detection at 215 nm, possible with DMC, allowed for the better detection of the phthalates by a factor of 10, compared with EA detection, best at a 254 nm wavelength. Using a core-shell silica column, HILIC separations of trans-ferulic acid, syringic acid, and vanillic acid were compared between acetonitrile (MeCN) and DMC as the organic portion of the mobile phase, from 80–95%. The analyte retention for DMC, when compared to MeCN, was about 1.5 times greater, with only a moderate increase in back pressure. Plate count and peak asymmetry were somewhat better for the DMC chromatograms, compared to those with MeCN. Seven mono- and di-hydroxybenzoic acid positional isomers could be resolved effectively with DMC. Sorbate and benzoate preservatives in commercial drinks were also determined. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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15 pages, 1348 KB  
Article
Improved Method for the Detection of Highly Polar Pesticides and Their Main Metabolites in Foods of Animal Origin: Method Validation and Application to Monitoring Programme
by Emanuela Verdini, Veronica Maria Teresa Lattanzio, Biancamaria Ciasca, Laura Fioroni and Ivan Pecorelli
Separations 2023, 10(1), 44; https://doi.org/10.3390/separations10010044 - 10 Jan 2023
Cited by 7 | Viewed by 3709
Abstract
The application of polar pesticides in agricultural production has been of great interest due to their low costs and their high effectiveness. For this reason, the possibility of their transfer to foods of animal origin is of great concern for human health. The [...] Read more.
The application of polar pesticides in agricultural production has been of great interest due to their low costs and their high effectiveness. For this reason, the possibility of their transfer to foods of animal origin is of great concern for human health. The manuscript describes the implementation and validation of an analytical method to detect polar pesticides, at regulatory levels, in three foods of animal origin, including bovine fat, chicken eggs, and cow milk. The method was fully validated to detect glyphosate, glufosinate, and their respective metabolites in the above-mentioned foods obtaining fit-for-purpose sensitivity, recoveries (76–119%), repeatability (≤20%), within-laboratory reproducibility (≤20%), and experimental measurement uncertainty less than 50% as required by the SANTE/11312/2021 criteria. Given the satisfactory results, the applicability of the method to additional molecules belonging to the same category (AMPA, cyanuric acid, ethephon, fosetyl aluminum, HEPA, maleic hydrazide, and N-acetyl-glyphosate) was also evaluated in order to meet possible future requests. Finally, the implemented method was applied to analyse samples over the period of March 2021 to August 2022 from two Italian regions (Umbria and Marche) within the national monitoring programme. In agreement with previously available data, none of the samples analysed showed the presence of glyphosate and glufosinate at levels above the legal limit. Full article
(This article belongs to the Special Issue Determination and Bio-Implications of Organic Pollutants in Food and Environmental Samples Based on Hyphenated Techniques)
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19 pages, 6437 KB  
Article
The Effect of the Elemental Composition of Municipal Sewage Sludge on the Phosphorus Recycling during Pyrolysis, with a Focus on the Char Chemistry—Modeling and Experiments
by Naeimeh Vali, Aurélie Combres, Aida Hosseinian and Anita Pettersson
Separations 2023, 10(1), 31; https://doi.org/10.3390/separations10010031 - 4 Jan 2023
Cited by 10 | Viewed by 2409
Abstract
The present study investigates how the original sewage sludge characteristics influence the composition of sewage sludge-based chars for land applications. Sewage sludge from two different wastewater treatment plants in Sweden was pyrolyzed at 500, 700, and 900 °C, and the resulting chars were [...] Read more.
The present study investigates how the original sewage sludge characteristics influence the composition of sewage sludge-based chars for land applications. Sewage sludge from two different wastewater treatment plants in Sweden was pyrolyzed at 500, 700, and 900 °C, and the resulting chars were analyzed. Thermodynamic equilibrium calculations (TEC), together with chemical fractionation, were implemented to simulate the char after the pyrolysis process at different temperatures. The results showed that, in general, for both the municipal sewage sludge (MSS), phosphorus (P) was significantly retained in the char at various temperatures. However, no specific correlation could be found between the pyrolysis temperature and the amount of P remaining. With regard to the heavy metals removed from the char after the pyrolysis reaction, the concentrations of copper, chromium, lead, nickel, zinc, and cadmium were below the limits of the Swedish regulations for farmland application. Full article
(This article belongs to the Special Issue Application of Green Separation Technology in Wastewater Treatment)
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28 pages, 2983 KB  
Review
Mass Spectrometric Methods for Non-Targeted Screening of Metabolites: A Future Perspective for the Identification of Unknown Compounds in Plant Extracts
by Michael Sasse and Matthias Rainer
Separations 2022, 9(12), 415; https://doi.org/10.3390/separations9120415 - 7 Dec 2022
Cited by 13 | Viewed by 6213
Abstract
Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique [...] Read more.
Phyto products are widely used in natural products, such as medicines, cosmetics or as so-called “superfoods”. However, the exact metabolite composition of these products is still unknown, due to the time-consuming process of metabolite identification. Non-target screening by LC-HRMS/MS could be a technique to overcome these problems with its capacity to identify compounds based on their retention time, accurate mass and fragmentation pattern. In particular, the use of computational tools, such as deconvolution algorithms, retention time prediction, in silico fragmentation and sophisticated search algorithms, for comparison of spectra similarity with mass spectral databases facilitate researchers to conduct a more exhaustive profiling of metabolic contents. This review aims to provide an overview of various techniques and tools for non-target screening of phyto samples using LC-HRMS/MS. Full article
(This article belongs to the Special Issue Novel Applications of Separation Technology)
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37 pages, 1644 KB  
Review
Heterogeneous Catalytic Ozonation: Solution pH and Initial Concentration of Pollutants as Two Important Factors for the Removal of Micropollutants from Water
by Savvina Psaltou, Manassis Mitrakas and Anastasios Zouboulis
Separations 2022, 9(12), 413; https://doi.org/10.3390/separations9120413 - 6 Dec 2022
Cited by 18 | Viewed by 2800
Abstract
There are several publications on heterogeneous catalytic ozonation; however, their conclusions and the comparisons between them are not always consistent due to the variety of applied experimental conditions and the different solid materials used as catalysts. This review attempts to limit the major [...] Read more.
There are several publications on heterogeneous catalytic ozonation; however, their conclusions and the comparisons between them are not always consistent due to the variety of applied experimental conditions and the different solid materials used as catalysts. This review attempts to limit the major influencing factors in order to reach more vigorous conclusions. Particularly, it highlights two specific factors/parameters as the most important for the evaluation and comparison of heterogeneous catalytic ozonation processes, i.e., (1) the pH value of the solution and (2) the initial concentration of the (micro-)pollutants. Based on these, the role of Point of Zero Charge (PZC), which concerns the respective solid materials/catalysts in the decomposition of ozone towards the production of oxidative radicals, is highlighted. The discussed observations indicate that for the pH range 6–8 and when the initial organic pollutants’ concentrations are around 1 mg/L (or even lower, i.e., micropollutant), then heterogeneous catalytic ozonation follows a radical mechanism, whereas the applied solid materials show their highest catalytic activity under their neutral charge. Furthermore, carbons are considered as a rather controversial group of catalysts for this process due to their possible instability under intense ozone oxidizing conditions. Full article
(This article belongs to the Special Issue Novel Separation Methods and Technology for Wastewater and Sludge Treatment)
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16 pages, 2001 KB  
Article
Bioactive Phytochemical Composition of Grape Pomace Resulted from Different White and Red Grape Cultivars
by Petronela Anca Onache, Elisabeta-Irina Geana, Corina Teodora Ciucure, Alina Florea, Dorin Ioan Sumedrea, Roxana Elena Ionete and Ovidiu Tița
Separations 2022, 9(12), 395; https://doi.org/10.3390/separations9120395 - 28 Nov 2022
Cited by 38 | Viewed by 5885
Abstract
Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used [...] Read more.
Grapes are rich in phenolic compounds, being important for human health with anti-inflammatory, antiatherosclerotic, antimutagenic, anticarcinogenic, antibacterial, antiviral, and antimicrobial activity. The winemaking of the grapes generates significant amounts of waste. These wastes contain bioactive compounds in their biomass that can be used as a source of food improvement or as a source of nutrition supplementation. This study looks at the content of bioactive compounds, the polyphenolic profile, and the antioxidant activity in different white and red grape pomaces. The investigation of bioactive characteristics (total polyphenols, total flavonoids, catechins, tannins, and antioxidant activity) was carried out by UV-Vis spectrophotometric methods, while the individual polyphenolic composition was investigated by target and screening UHPLC-HRMS/MS analysis. Principal components (PCA) and the heat maps analysis allows the discrimination between the grape pomace resulted from white grape cultivars (Muscat Ottonel and Tamaioasa Romaneasca) and red grape pomaces (Cabernet Sauvignon, Merlot, Feteasca Neagra, Burgund Mare, Pinot Nore), with the identification of the specific phenolic compounds for each grape pomace type. Full article
(This article belongs to the Section Analysis of Food and Beverages)
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28 pages, 1968 KB  
Review
Metal-Chelating Peptides Separation Using Immobilized Metal Ion Affinity Chromatography: Experimental Methodology and Simulation
by Rachel Irankunda, Jairo Andrés Camaño Echavarría, Cédric Paris, Loïc Stefan, Stéphane Desobry, Katalin Selmeczi, Laurence Muhr and Laetitia Canabady-Rochelle
Separations 2022, 9(11), 370; https://doi.org/10.3390/separations9110370 - 14 Nov 2022
Cited by 20 | Viewed by 9639
Abstract
Metal-Chelating Peptides (MCPs), obtained from protein hydrolysates, present various applications in the field of nutrition, pharmacy, cosmetic etc. The separation of MCPs from hydrolysates mixture is challenging, yet, techniques based on peptide-metal ion interactions such as Immobilized Metal Ion Affinity Chromatography (IMAC) seem [...] Read more.
Metal-Chelating Peptides (MCPs), obtained from protein hydrolysates, present various applications in the field of nutrition, pharmacy, cosmetic etc. The separation of MCPs from hydrolysates mixture is challenging, yet, techniques based on peptide-metal ion interactions such as Immobilized Metal Ion Affinity Chromatography (IMAC) seem to be efficient. However, separation processes are time consuming and expensive, therefore separation prediction using chromatography modelling and simulation should be necessary. Meanwhile, the obtention of sorption isotherm for chromatography modelling is a crucial step. Thus, Surface Plasmon Resonance (SPR), a biosensor method efficient to screen MCPs in hydrolysates and with similarities to IMAC might be a good option to acquire sorption isotherm. This review highlights IMAC experimental methodology to separate MCPs and how, IMAC chromatography can be modelled using transport dispersive model and input data obtained from SPR for peptides separation simulation. Full article
(This article belongs to the Section Bioanalysis/Clinical Analysis)
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