Journal Description
Separations
Separations
- formerly Chromatography - is an international, peer-reviewed, open access journal on separation and purification science and technology in all areas of chemical, biological, physical science, and separation performance published monthly online by MDPI. The Central European Group of Separation Sciences (CEGSS) is affiliated with Separations and their members receive discounts on the article processing charges.
- Open Access— free for readers, with article processing charges (APC) paid by authors or their institutions.
- High Visibility: indexed within Scopus, SCIE (Web of Science), CAPlus / SciFinder, and other databases.
- Rapid Publication: manuscripts are peer-reviewed and a first decision is provided to authors approximately 13.6 days after submission; acceptance to publication is undertaken in 2.9 days (median values for papers published in this journal in the second half of 2023).
- Recognition of Reviewers: reviewers who provide timely, thorough peer-review reports receive vouchers entitling them to a discount on the APC of their next publication in any MDPI journal, in appreciation of the work done.
- Companion journal: Purification.
Impact Factor:
2.6 (2022);
5-Year Impact Factor:
2.7 (2022)
Latest Articles
Identification of Quality Markers in Schisandra chinensis (Turcz.) Baill. Using UPLC-Q-Extractive Orbitrap/MS, Chemometric Analysis, and Network Pharmacology
Separations 2024, 11(3), 88; https://doi.org/10.3390/separations11030088 - 18 Mar 2024
Abstract
Chemical composition is a critical factor for determining the efficacy of any traditional Chinese medicine (TCM) and can be used as an indicator of commercial quality. To develop a new strategy for discovering potential quality markers (Q-markers) of TCM by integrating ultra-performance liquid
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Chemical composition is a critical factor for determining the efficacy of any traditional Chinese medicine (TCM) and can be used as an indicator of commercial quality. To develop a new strategy for discovering potential quality markers (Q-markers) of TCM by integrating ultra-performance liquid chromatography-Q-extractive orbitrap/mass spectrometry (UPLC-Q-Extractive Orbitrap/MS), chemometric analysis, and network pharmacology, using Schisandra chinensis (Turcz.) Baill. (S. chinensis) as an example. The chemical profiling of S. chinensis was performed using UPLC-Q-Extractive Orbitrap/MS, followed by identification of hepatoprotective Q-markers through a comprehensive understanding of chemometric analysis and virtual target prediction of network pharmacology. Six compounds were considered potent candidates for Q-markers, which were identified as schisandrol A (6), angeloylgomisin H (10), schisantherin A (17), schisantherin B (18), schisandrin A (23), and schisandrin C (26). All Q-markers exhibited significant hepatoprotective activity, as evidenced by in vitro experiments. Subsequently, a method for simultaneous quantification was established and employed to analyse seven batches of S. chinensis. Therefore, the integrated approach of UPLC-Q-Extractive Orbitrap/MS, chemometrics, and network pharmacology proved to be an effective strategy for the discovery of Q-markers that can assist in assessing the overall chemical consistency of samples and provide a basis for quality evaluation of the material basis of S. chinensis.
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(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)
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Targeted Offline Two-Dimensional HPLC and UHPLC-Orbitrap-MS Combined with Molecular Networking Reveal the Effect of Processing on Chemical Constituents of Xuetong (the Stem of Kadsura heteroclita)
by
Hanwen Yuan, Wei Su, Ling Liang, Qingling Xie, Mengying Lyu, Huanghe Yu, Bin Li and Wei Wang
Separations 2024, 11(3), 87; https://doi.org/10.3390/separations11030087 - 18 Mar 2024
Abstract
Xuetong, the dried stem of Kadsura heteroclita (Roxb.) Craib, is a traditional Tujia medicine extensively used to treat rheumatoid arthritis (RA). All traditional Chinese medicines (TCMs) necessitate a processing stage called “Paozhi” before clinical application. However, there is a dearth of research concerning
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Xuetong, the dried stem of Kadsura heteroclita (Roxb.) Craib, is a traditional Tujia medicine extensively used to treat rheumatoid arthritis (RA). All traditional Chinese medicines (TCMs) necessitate a processing stage called “Paozhi” before clinical application. However, there is a dearth of research concerning the processing methods employed for Xuetong. To investigate the impact of vinegar and wine processing on the chemical constituents of Xuetong, this study devised a targeted offline two-dimensional (2D) high-performance liquid chromatography (HPLC) and ultra-high-performance liquid chromatography-orbitrap mass spectrometry (UHPLC-orbitrap-MS) method. By incorporating various MS data-processing techniques, such as molecular networking technology, fragment-ion similarity searching (FISh), online and offline database matching, and fragmentation pattern analysis, a total of 158 components were identified in Xuetong. Among them, 14 were verified by comparison with the reference standards. Notably, aside from triterpenoids and lignans, catechin derivatives were found to be the predominant constituents of Xuetong, and their levels exhibited a significant decrease following processing. This method significantly improved peak capacity and resolution, overcoming the limitations of 1D LC in simultaneously analyzing highly polar catechin derivatives and less polar triterpenoids and lignans. Moreover, the developed method shows promise for Xuetong’s quality control.
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(This article belongs to the Special Issue Applications of Separation and Purification Techniques for Natural Products Derived from Plants Source)
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The Phosphorus Adsorption and Recovery of Mg/Fe-LDHs Mulberry Rod Biochar Composite
by
Meina Liang, Zimeng Wu, Haiyan Cao, Kun Dong, Shaoyuan Bai and Dunqiu Wang
Separations 2024, 11(3), 86; https://doi.org/10.3390/separations11030086 - 18 Mar 2024
Abstract
Mg/Fe layered bimetallic oxide mulberry rod biochar composites (MFBCs) were prepared from mulberry rods and characterized using electron microscopy scanning (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). We investigated the adsorption properties of MFBCs for phosphorus, which
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Mg/Fe layered bimetallic oxide mulberry rod biochar composites (MFBCs) were prepared from mulberry rods and characterized using electron microscopy scanning (SEM), X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). We investigated the adsorption properties of MFBCs for phosphorus, which was recovered via crystallization using calcium chloride as a precipitant. According to the findings, the MFBC is a layered bimetallic oxide with a specific surface area of 70.93 m2·g−1. Its point of zero charge values, or pHzpc, was 7.66. The removal of phosphorus usingMFBCs gradually decreased with increasing pH, and the optimum pH for phosphorus removal was 4.0. The maximum phosphorus adsorption by MFBCs at 298 K was 29.682 mg·g−1 for MFBCs. The adsorption process of phosphorus onto MFBCs is a heat absorption process, and the adsorption isothermal data of phosphorus onto MFBCs fit with the Langmuir adsorption isothermal model. Phosphorus recovery is achieved when calcium chloride is added to the phosphate-enriched desorption solution at a Ca/P molar ratio of 2.2. The phosphorus product obtained from this process is very pure hydroxyphospapatite. The recovery rate of phosphorus in the desorption solution is 99.64%.
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(This article belongs to the Special Issue Removal and Recovery of Nitrogen and Phosphorus from Wastewater)
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Chemical Characterization of Human Body Odor Headspace Components
by
A. Celeste Medrano, Ariela Cantu, Edgar O. Aviles-Rosa, Nathaniel J. Hall, Michele N. Maughan, Jenna D. Gadberry and Paola A. Prada-Tiedemann
Separations 2024, 11(3), 85; https://doi.org/10.3390/separations11030085 - 15 Mar 2024
Abstract
This study focused on evaluating human body odor volatiles using a chamber approach. Ten participants were asked to sit inside the chamber for 1 h, while using SPME as the extraction technique for vapor sampling. A total of 105 compounds were detected across
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This study focused on evaluating human body odor volatiles using a chamber approach. Ten participants were asked to sit inside the chamber for 1 h, while using SPME as the extraction technique for vapor sampling. A total of 105 compounds were detected across participants, with nonanal having the highest frequency. PCA statistical analysis depicted tighter clustering in female whole-body odor profiles when compared to males, thus corroborating gender odor differences. Concurrently, various biospecimens (hand, axillary, breath) from the same participants allowed for a comparison between whole-body and individual biospecimen odor signatures. When comparing whole-body sampling and distinctive biospecimens, nonanal and decanal were the only odor volatiles shared. Statistical clustering depicted higher similarity within the odor profiles of individual biospecimens compared to odor profiles of the whole body, indicating distinctiveness of the odor chemical landscape as a function of sampling region. Overall, this study demonstrated that SPME-GC/MS methodology was successful in the extraction, detection, and identification of previously reported human scent volatiles when employing the human chamber for whole-body sampling. Our presented testing paradigm allows for a direct comparison of odor volatiles across the full body and specific body locations that allows odor markers to be furthered exploited for diagnostic and biological detection contexts.
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(This article belongs to the Special Issue Chemical Separations in Criminalistics)
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Evaluation of Carbonized Corncobs for Removal of Microcystins and Nodularin-R from Water
by
Hasaruwani S. Kiridena, Sharmila I. Thenuwara, Manjula M. Kandage, Norman Peiffer, Michal Marszewski and Dragan Isailovic
Separations 2024, 11(3), 84; https://doi.org/10.3390/separations11030084 - 13 Mar 2024
Abstract
Microcystins (MCs) and nodularins (NODs) are cyanotoxins that can be found in water bodies during cyanobacterial harmful algal blooms (cyanoHABs). Consumption of water contaminated with cyanotoxins leads to health risks for humans and animals. Herein, corncob-based biochar and activated carbon (AC) were initially
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Microcystins (MCs) and nodularins (NODs) are cyanotoxins that can be found in water bodies during cyanobacterial harmful algal blooms (cyanoHABs). Consumption of water contaminated with cyanotoxins leads to health risks for humans and animals. Herein, corncob-based biochar and activated carbon (AC) were initially investigated for the sorption of six common MC congeners (MC-RR, MC-YR, MC-LR, MC-LA, MC-LW, and MC-LF) and nodularin-R (NOD-R) from spiked water. Biochar was prepared by refluxing commercial corncob with HCl and heating it to 250, 300, or 350 °C. AC was prepared by chemical activation of corncob with H3PO4 at 500 °C under a nitrogen atmosphere. Low-temperature nitrogen adsorption measurements confirmed that H3PO4-AC has a higher specific surface area (≈1100 m2/g) and total pore volume (≈0.75 cm3/g) than biochar and commercial AC. H3PO4-AC showed the maximum efficacy, among all corncob-based sorbents, to remove MCs and NOD-R from water as confirmed by experiments that involved sample analyses by ultrahigh-pressure liquid chromatography-mass spectrometry (UHPLC-MS). The effect of natural organic matter (NOM) on the adsorption of MCs was checked by incubating sorbents with Lake Erie water collected during cyanoHABs from 2020 to 2022. The total concentration (extracellular and intracellular) of studied MC congeners ranged from 1.37 µg/L to 438.51 µg/L and 50 mg of H3PO4-AC completely removed them from 3 mL of lake water. The effect of water pH on cyanotoxin adsorption was studied at pH values of 5.5, 7.0, and 8.5 at both a lower (10 μg/L each) and a higher (50 μg/L each) toxin concentration. Removal was influenced by solution pH at both concentrations when using biochar, while only at higher toxin concentration when using H3PO4-AC. At higher MC and NOD-R concentrations, competitive adsorption was prominent, and overall, the adsorption increased at acidic pH (5.5). The study results suggest that processed corncobs can remove a significant amount of MCs and NOD-R from water, and the measured sorption capacity of H3PO4-AC was ~20 mg of MC-LR and NOD-R per g of this sorbent.
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(This article belongs to the Special Issue Adsorption Technique for Water Purification)
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Whiter and Greener RP-HPLC Method for Simultaneous Determination of Dorzolamide, Brinzolamide, and Timolol Using Isopropanol as a Sustainable Organic Solvent in the Mobile Phase
by
Sami El Deeb, Khalid Abdelsamad and Maria Kristina Parr
Separations 2024, 11(3), 83; https://doi.org/10.3390/separations11030083 - 12 Mar 2024
Abstract
A sustainable reversed-phase chromatographic method has been developed and validated for the simultaneous determination of three active pharmaceutical ingredients, dorzolamide, brinzolamide, and timolol, used to treat glaucoma. The eco-friendly solvent isopropanol has been used as an organic mobile phase constituent. According to the
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A sustainable reversed-phase chromatographic method has been developed and validated for the simultaneous determination of three active pharmaceutical ingredients, dorzolamide, brinzolamide, and timolol, used to treat glaucoma. The eco-friendly solvent isopropanol has been used as an organic mobile phase constituent. According to the Hansen space green solvent selection tool, isopropanol has a G score of 6.5, comparable to ethanol, which has a G score of 6.6. The mobile phase consists of isopropanol: aqueous sodium acetate buffer (0.1 M, pH 4.25) in the ratio of 10:90 (v/v). The flow rate was maintained at 1 mL/min. Dorzolamide and brinzolamide were detected at 254 nm, and timolol was detected at 295 nm. A high-purity silica with a polymeric C18 modification column (150 × 4.6 mm, 5 µm particle size) was used for this separation. The three compounds were eluted within 8 min. The method was validated according to ICH guidelines. The calibration curves were linear in the range of 20–70 µg/mL, 40–140 µg/mL, and 20–70 µg/mL for dorzolamide, brinzolamide, and timolol, respectively. The LODs were found to be 1.61 µg/mL, 1.60 µg/mL, and 3.16 µg/mL for dorzolamide, brinzolamide, and timolol, respectively. Good accuracy and precision were obtained for the three compounds. The greenness and whiteness of the method were indicated using the AGREE, ChlorTox, and RGB12 tools.
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(This article belongs to the Section Chromatographic Separations)
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Unveiling Novel Chaotropic Chromatography Method for Determination of Pralidoxime in Nerve Agent Antidote Autoinjectors
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Bohyun Shin, Hyung-seung Kim, Ji-Youn Lee, Sumin Seo, Cho Hee Jeong, Eunbin Bae, Jiyu Kim, Hyojeong Lee, Donghee Lee, Dong-Kyu Lee and Sang Beom Han
Separations 2024, 11(3), 82; https://doi.org/10.3390/separations11030082 - 07 Mar 2024
Abstract
Pralidoxime chloride, a highly hydrophilic antidote, cannot be effectively separated by reverse-phase high-performance liquid chromatography (RP-HPLC), unless the mobile-phase composition is varied. However, the use of ion-pairing reagents for pralidoxime separation is hindered by the persistent contamination of the stationary phase or chromatography
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Pralidoxime chloride, a highly hydrophilic antidote, cannot be effectively separated by reverse-phase high-performance liquid chromatography (RP-HPLC), unless the mobile-phase composition is varied. However, the use of ion-pairing reagents for pralidoxime separation is hindered by the persistent contamination of the stationary phase or chromatography system inside the HPLC system. Thus, this study aimed to develop a simple, rapid, and robust method based on RP-HPLC to determine pralidoxime chloride in antidote autoinjectors using a chaotropic salt as the mobile-phase additive. The use of UV detection at 270 nm allowed for the simultaneous detection of pralidoxime chloride and the internal standard, pyridine-2-aldoxime. The addition of chaotropic salts (NaPF6, NaBF4, and NaClO4) and an ionic liquid ([EMIM]PF6) increased the retention time of pralidoxime chloride. Among them, NaPF6 exhibited the highest capacity factor in the reverse-phase C18 column. Increasing the salt concentration increased the capacity factor and the number of theoretical plates. Analytical method validation was performed to assess the linearity, accuracy, precision, recovery, and repeatability, according to the Ministry of Food and Drug Safety guidelines. Additionally, this newly developed method exhibits an adequate separation capability, making it a potential substitute for the current method employed in the United States/Korean Pharmacopoeia, and it ensures the necessary durability to maintain the robustness and reliability of the analytical system.
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(This article belongs to the Special Issue Advances in the Chromatographic Separation and Analysis of Natural Products/Medicines)
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A Sustainable Approach for Enhancing Stability and Bioactivity of Allium ursinum Extract for Food Additive Applications
by
Alena Stupar, Senka Vidović, Jelena Vladić, Tanja Radusin and Aleksandra Mišan
Separations 2024, 11(3), 81; https://doi.org/10.3390/separations11030081 - 06 Mar 2024
Abstract
Utilizing natural plant extracts as food additives represents a promising strategy for enhancing the quality, nutritional value, and safety of food products, benefiting both consumers and the environment. Therefore, the primary objective of this study was to develop an environmentally sustainable process for
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Utilizing natural plant extracts as food additives represents a promising strategy for enhancing the quality, nutritional value, and safety of food products, benefiting both consumers and the environment. Therefore, the primary objective of this study was to develop an environmentally sustainable process for the production of solid powder derived from Allium ursinum liquid extract, with the intent of utilizing it as a natural food additive. To address the challenge of instability and enhance the solubility of bioactive compounds in A. ursinum extracts obtained through subcritical water extraction, this study employed the spray drying process. Notably, the results demonstrated the remarkable efficiency of the spray drying process, with maltodextrin as a carrier, yielding uniformly encapsulated particles with an average size of approximately 4 µm, spherical shape with smooth, intact surfaces. The most optimal conditions for achieving the highest content of total phenolics (23.10 mg GAE/g) and total flavonoids (4.92 mg CE/g) in the A. ursinum extract were identified, involving an inlet temperature of 120 °C and an 80% maltodextrin concentration. The encapsulated powders showed excellent stability, with minimal loss of total phenolics (12.64%) and total flavonoids (10.52%) after three months of storage. Physicochemical analysis confirmed the successful preservation of bioactive compounds through microencapsulation using maltodextrin, suggesting its potential for application in innovative food or pharmaceutical products.
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(This article belongs to the Section Analysis of Natural Products and Pharmaceuticals)
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Exploring Humic Acid as an Efficient and Selective Adsorbent for Lead Removal in Multi-Metal Coexistence Systems: A Review
by
Shuwen Xue, Yunhu Hu, Keji Wan and Zhenyong Miao
Separations 2024, 11(3), 80; https://doi.org/10.3390/separations11030080 - 04 Mar 2024
Abstract
Water pollution poses a global threat to human health, particularly in terms of ensuring a safe supply of drinking water. The accumulation of heavy metals from various water sources is increasing, driving the search for effective and environmentally friendly approaches and materials for
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Water pollution poses a global threat to human health, particularly in terms of ensuring a safe supply of drinking water. The accumulation of heavy metals from various water sources is increasing, driving the search for effective and environmentally friendly approaches and materials for metal removal. This review investigates the selective adsorption of Pb2+ by humic acid (HA) in a multi-metal coexistence solution. The focus is on discussing approaches to the structural identification of HA, highlighting that separation techniques are an effective method to reduce its heterogeneity. Starting from the key structural units of HA, the study reveals the interaction between HA and heavy metals. Approaches to enhance Pb2+ selective adsorption are explored, proposing that introducing activating groups, Ca ion exchange, and optimizing pore structures are effective approaches for improving lead ion selective adsorption. Ca2+ activation is suggested as a future research direction for lead-selective adsorption. Additionally, attaining lead selective adsorption through pH regulation’s significance is emphasized. This research contributes to a fundamental understanding of HA’s role as a selective lead adsorbent while offering practical implications for developing environmentally friendly adsorbent materials. The results aim to advance knowledge in environmental science and water treatment.
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(This article belongs to the Special Issue Selective Separation of Heavy Metals from Water/Soil)
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A Chemical Safety Assessment of Lyocell-Based Activated Carbon Fiber with a High Surface Area through the Evaluation of HCl Gas Adsorption and Electrochemical Properties
by
Jong Gu Kim and Byong Chol Bai
Separations 2024, 11(3), 79; https://doi.org/10.3390/separations11030079 - 02 Mar 2024
Abstract
This study investigates lyocell-based activated carbon fibers (ACFs) for their suitability in adsorbing and electrochemically detecting toxic HCl gas. ACFs were prepared via steam activation, varying temperature (800–900 °C) and time (40–240 min) to assess their adsorption and sensing capabilities. The adjustment of
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This study investigates lyocell-based activated carbon fibers (ACFs) for their suitability in adsorbing and electrochemically detecting toxic HCl gas. ACFs were prepared via steam activation, varying temperature (800–900 °C) and time (40–240 min) to assess their adsorption and sensing capabilities. The adjustment of activation temperature and reaction time aimed to regulate the uniformity of the pore structure and pore size of the active reaction area, as well as the number of reaction sites in the ACFs. Optimal ACFs were achieved at 900 °C for 50 min, exhibiting the highest specific surface area (1403 m2/g) and total pore volume (0.66 cm3/g). Longer reaction times resulted in pore formation and disorder, reducing mechanical strength. The ACFs prepared under optimal conditions demonstrated a rapid increase in resistance during sensor measurement, indicating a significant sensitivity to HCl gas. These findings suggest the potential of ACFs for efficient HCl gas adsorption (1626.20 mg/g) and highlight the importance of activation parameters in tailoring their properties for practical applications.
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(This article belongs to the Special Issue Development and Applications of Porous Materials in Adsorptions)
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Comparison of Acid- and Base-Modified Biochar Derived from Douglas Fir for Removal of Copper (II) from Wastewater
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Beatrice Arwenyo, Prashan M. Rodrigo, Olalekan A. Olabode, Hashani P. Abeysinghe, Jessie N. Tisdale, Rose C. Azuba and Todd E. Mlsna
Separations 2024, 11(3), 78; https://doi.org/10.3390/separations11030078 - 01 Mar 2024
Abstract
Copper is a non-biodegradable heavy metal, and high levels in water bodies cause serious environmental and health issues. Douglas fir biochar has a higher number of carboxylic, phenolic, and lactonic groups, which provide suitable active sites for copper removal. Douglas fir biochar (BC)
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Copper is a non-biodegradable heavy metal, and high levels in water bodies cause serious environmental and health issues. Douglas fir biochar has a higher number of carboxylic, phenolic, and lactonic groups, which provide suitable active sites for copper removal. Douglas fir biochar (BC) was modified using 20% solutions of KOH (KOH/BC), H2SO4, (H2SO4/BC), and Na2CO3 (Na2CO3/BC). All materials were characterized using SEM, SEM-EDS, FTIR, TGA, XRD, BET, and elemental analysis. These modifications were done to compare the activations of those sites by measuring copper removal efficiencies. KOH/BC, H2SO4/BC, and Na2CO3/BC materials gave surface areas of 389.3, 326.7, and 367.9 m2 g−1, respectively, compared with pristine biochar with a surface area of 578.9 m2 g−1. The maximum Langmuir adsorption capacities for Na2CO3/BC, KOH/BC, BC, and H2SO4/BC were 24.79, 18.31, 17.38, and 9.17 mg g−1, respectively. All three modifications gave faster kinetics at 2 mg/L initial copper concentrations (pH 5) compared with pristine BC. The copper removal efficiency was demonstrated in four different spiked real water matrices. The copper removals of all four water matrices were above 90% at 2 mg/L initial concentration with a 2 g/L biochar dosage. The competitive effects of Pb2+, Zn2+, Cd2+, and Mg2+ were studied at equimolar concentrations of Cu2+ and competitive ions for all four materials.
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(This article belongs to the Special Issue Adsorption Technique for Water Purification)
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Construction of High-Activity Nano-NiTiO3/g-C3N4 Composite Catalysts for Enhanced Photodegradation Activities under Visible Light
by
Da Li, Zhan Yang, Kun Wang, Lan Zhang, Linglong Shi, Abdul Qadeer, Jiao Dong and Haoyu Ren
Separations 2024, 11(3), 77; https://doi.org/10.3390/separations11030077 - 01 Mar 2024
Abstract
Nickel titanate (NiTiO3) semiconductors and graphitic carbon nitride (g-C3N4) have attracted great attention as photocatalysts in the degradation of environmental pollutants because of their visible-light-driven activity. But the utilizations of both semiconductors are limited by their low
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Nickel titanate (NiTiO3) semiconductors and graphitic carbon nitride (g-C3N4) have attracted great attention as photocatalysts in the degradation of environmental pollutants because of their visible-light-driven activity. But the utilizations of both semiconductors are limited by their low specific surface area. In this study, a nano-NiTiO3/g-C3N4 photocatalyst was successfully synthesized by optimizing the preparation method of photocatalyst precursors. Compared with the bulk g-C3N4 and bulk NiTiO3/g-C3N4 composite photocatalysts, the nano-NiTiO3/g-C3N4 composite catalyst displayed a larger specific surface area, a more abundant pore size structure, and superior carrier separation capabilities. According to the pseudo-first-order, the degradation rate of MB was more than 2.5–19.7 times higher than that of previous studies. The superoxide radicals (·O2−) and holes (h+) played significant roles in the photocatalytic reaction of MB. This study provides a new idea for the synthesis of photocatalysts and the improvement in photocatalytic performance.
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(This article belongs to the Special Issue Advanced Functional Materials for Wastewater Treatment and Purification)
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Pharmaceutical Screening of Bat Feces and Their Applications and Risks in Traditional Chinese Medicine
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Kou-Toung Chung, Ching-Lung Lin, Wu-Chang Chuang, Ming-Chung Lee, Li-Wen Chen and Chung-Hsin Wu
Separations 2024, 11(3), 76; https://doi.org/10.3390/separations11030076 - 29 Feb 2024
Abstract
Bat feces have been reported in traditional Chinese medicine (TCM) books to have the effect of reducing fever and improving eyesight, but the mechanism of vision improvement still needs further research. To this end, we used 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and liquid
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Bat feces have been reported in traditional Chinese medicine (TCM) books to have the effect of reducing fever and improving eyesight, but the mechanism of vision improvement still needs further research. To this end, we used 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and liquid chromatography/tandem mass spectrometry (LC/MS/MS) to analyze the antioxidant capacity of and the types of vitamins in bat feces. We hoped to screen the pharmacological components of bat feces and to explain the role that these components may play in treating visual deterioration. Our results found that bat feces had a good antioxidant capacity and mainly contained vitamins B1 (thiamine), B2 (riboflavin), B3 (nicotinamide), B3 (nicotinic acid), and B5 (pantothenic acid). Although these vitamins may help to maintain the health of the optic nerve and cornea, the vitamin content of bat feces is low, but the heavy metal content is high, as shown using inductively coupled plasma–mass spectrometry (ICP-MS) analysis. Therefore, we suggest that the use of bat feces as TCM to improve vision should be strictly restricted.
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(This article belongs to the Special Issue Isolation of Natural Products and Their Application in Pharmaceuticals)
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Effect of Positively Charged Lipids (DOTAP) on the Insertion of Carbon Nanotubes into Liposomes and the Separation Performance of Thin-Film Nanocomposite Membranes
by
Jianjun Zhao, Junqing Sun, Kefeng Zhang, Shan Wang, Wande Ding and Zhengping Li
Separations 2024, 11(3), 75; https://doi.org/10.3390/separations11030075 - 28 Feb 2024
Abstract
A liposome vesicle is an ideal carrier for carbon nanotubes (CNTs) serving as the water channel that allows for the fast transport of water molecules, thus enhancing membrane permeability. However, a low quantity of CNTs inserted into the liposome vesicle is an important
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A liposome vesicle is an ideal carrier for carbon nanotubes (CNTs) serving as the water channel that allows for the fast transport of water molecules, thus enhancing membrane permeability. However, a low quantity of CNTs inserted into the liposome vesicle is an important factor that limits the further improvement of the membrane flux. In the present study, a positively charged lipid, (2,3-dioleoyloxy-propyl)-trimethylammonium-chloride (DOTAP), was introduced to 1,2-dioleoyl-sn-glycero-3-phosphoethanolamineon (DOPE) liposome vesicles to tailor the vesicle charge so as to evaluate the effect of positively charged DOTAP on the insertion of CNTs into liposomes and the separation performance of thin-film nanocomposite (TFN) membranes. The results show that the addition of DOTAP increased the quantity of CNTs inserted into the liposome vesicles, as the shrinkage rate (k) and permeability (Pf) of the liposome vesicles presented an obvious increase with the increased content of DOTAP in the liposome vesicles. Moreover, it contributed to a 252.3% higher water flux for TFN membranes containing DOPE/DOTAP2:1-CNT liposomes (the mass ratio between DOPE and DOTAP was 2:1) than thin-film composite (TFC) membranes. More importantly, it presented a 106.7% higher water flux for TFN membranes containing DOPE/DOTAP4:1-CNT liposomes (the mass ratio between DOPE and DOTAP was 4:1), which originated from the greater number of water channels that the CNTs provided in the liposome vesicles. Overall, positively charged DOTAP effectively tailored the vesicle charge, which provided a better carrier for the insertion of a greater quantity of CNTs and contributed to the higher permeability of the TFN membranes.
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(This article belongs to the Special Issue Preparation of Membranes and Their Application in Separation)
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Mechanism of Alleviating Acute Lung Injury in Mice from Serum Metabolomics Analysis of Cordyceps fumosorosea
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Tahir Khan, Jinna Zhou, Yingqi Guo, Donghai Hou, Na Pi, Yinlong Yang and Hong Yu
Separations 2024, 11(3), 74; https://doi.org/10.3390/separations11030074 - 27 Feb 2024
Abstract
Cordyceps fumosorosea is a common species within the Cordyceps genus. In this study, the protective effect of Cordyceps fumosorosea mycelium was investigated to clarify the potential mechanism of alleviating acute lung injury in mice using serum metabolomic analysis, which could provide a theoretical
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Cordyceps fumosorosea is a common species within the Cordyceps genus. In this study, the protective effect of Cordyceps fumosorosea mycelium was investigated to clarify the potential mechanism of alleviating acute lung injury in mice using serum metabolomic analysis, which could provide a theoretical basis for the clinical application of C. fumosorosea. Sixty mice were divided into six groups (NS, LPS, MIX, COR, COC and DMX). Lung cell nuclei were analyzed using hematoxylin and eosin staining and cellular changes were observed using transmission electron microscopy (TEM). Metabolomic analyses using liquid chromatography-mass spectrometry (LC-MS) were used to identify various compounds. In all six groups, lung nuclear inflammation was observed in the COR, COC and DMX groups, whereas the NS, LPS and MIX groups showed no cellular changes, indicating good health. Metabolomic analysis using LC-MS identified 1607 compounds across various classes. Statistical analyses, including the coefficient of variation and OPLS-DA, revealed distinct metabolic proles, indicating significant changes after the consumption of C. fumosorosea mycelia. Lipids constituted the largest proportion (30.37%) of the 30 identified classes and subclasses of metabolites. A total of 617 differentially accumulated metabolites (DAMs) were identified, both unique and shared between comparisons. Metabolite analysis identified 617 differentially accumulated metabolites, with 493 common to the LPS vs. MIX group, 75 in the LPS vs. NS group and 49 in the LPS vs. NS group and LPS vs. MIX group. This comprehensive investigation suggests that C. fumosorosea mycelia treatment holds promise as a therapeutic intervention for lung injury, influencing both the histopathological (lung) features and serum metabolic profiles.
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(This article belongs to the Section Materials in Separation Science)
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Accelerated Development of AAV Purification Process Using a High-Throughput and Automated Crossflow System
by
Sónia Mendes, Tiago Q. Faria, André Nascimento, Marc Noverraz, Franziska Bollmann, Piergiuseppe Nestola, António Roldão, Cristina Peixoto and Ricardo J. S. Silva
Separations 2024, 11(3), 73; https://doi.org/10.3390/separations11030073 - 26 Feb 2024
Abstract
Adeno-associated viruses (AAV) are currently predominant viral transfer tools for gene therapy, and efforts are being made to design faster and more efficient methods and technologies for their manufacturing. The early selection of high-performing filters is essential for developing an ultrafiltration and diafiltration
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Adeno-associated viruses (AAV) are currently predominant viral transfer tools for gene therapy, and efforts are being made to design faster and more efficient methods and technologies for their manufacturing. The early selection of high-performing filters is essential for developing an ultrafiltration and diafiltration (UF/DF) process, especially when feed material is scarce, and timelines are short. However, few methods and technologies exist to enable process optimization with multiple variations in a single run. In this study, we explored the potential of Ambr® Crossflow for high-throughput, automated screening of different membrane materials, pore sizes and different process conditions for the UF/DF step of AAV8. The best overall performance was obtained with a 100 kDa PES flat sheet cassette. The UF/DF process was further transferred to a larger scale to the Sartoflow® Smart Tangential Flow Filtration (TFF) system using a 100 kDa PES Sartocon® Slice 200 cassette and compared to a 100 kDa PES hollow fiber. Virus recovery, permeate flux and total protein removal values of the flat sheet cassette were similar to those achieved in small-scale devices, and higher than those of the hollow fiber, thus demonstrating similar performance at a larger process scale. The high-throughput, automated method described herein allowed to screen multiple materials and process parameters of a UF/DF process in a time- and resource-efficient way, making it a useful tool to accelerate early-stage downstream process development of AAV.
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(This article belongs to the Section Separation Engineering)
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The Effect of Rotation on Gas Storage in Nanoporous Materials
by
Athanasios Ch. Mitropoulos, Ramonna I. Kosheleva, Margaritis Kostoglou and Thodoris D. Karapantsios
Separations 2024, 11(3), 72; https://doi.org/10.3390/separations11030072 - 24 Feb 2024
Abstract
Nanoporous materials offer a promising solution for gas storage applications in various scientific and engineering domains. However, several crucial challenges need to be addressed, including adsorptive capacity, rapid loading, and controlled gas delivery. A potential approach to tackle these issues is through rotation-based
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Nanoporous materials offer a promising solution for gas storage applications in various scientific and engineering domains. However, several crucial challenges need to be addressed, including adsorptive capacity, rapid loading, and controlled gas delivery. A potential approach to tackle these issues is through rotation-based methods. In this study, we investigate the impact of rotation on CO2 adsorption using activated carbon, both at the early and late stages of the adsorption process. Towards this direction, three sets of experiments were conducted: (i) adsorption isotherm with rotation at each gas loading, (ii) adsorption kinetics with multiple rotations performed in sequence 15 min after CO2 introduction, and (iii) adsorption kinetics with a single rotation after 40 h of adsorption and repetition after another 20 h. For the first two cases, the comparison was performed by respective measurements without rotation, while for the last case, results were compared to a theoretical pseudo-first-order kinetic curve. Our findings demonstrate that rotation enhances the adsorptive capacity by an impressive 54%, accelerates kinetics by a factor of 3.25, and enables controllable gas delivery by adjusting the angular velocity. These results highlight rotation as a promising technique to optimize gas storage in nanoporous materials, facilitating advancements in numerous scientific and engineering applications.
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(This article belongs to the Topic Porous Materials for Energy and Environment Applications)
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Continuous Purification of Biodiesel with Deep Eutectic Solvent in a Laboratory Karr Column
by
Aleksandra Sander, Ana Petračić, Domagoj Vrsaljko, Jelena Parlov Vuković, Patricija Hršak and Antonija Jelavić
Separations 2024, 11(3), 71; https://doi.org/10.3390/separations11030071 - 24 Feb 2024
Abstract
Following the trend of transport decarbonization, biodiesel has become a promising alternative fuel option. Its production includes multiple steps, all of which can be time-consuming and energy intensive. Improving any of these steps could bring considerable environmental and economic benefits. The utilization of
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Following the trend of transport decarbonization, biodiesel has become a promising alternative fuel option. Its production includes multiple steps, all of which can be time-consuming and energy intensive. Improving any of these steps could bring considerable environmental and economic benefits. The utilization of deep eutectic solvents (DESs) for glycerol extraction from crude biodiesel has predominantly been explored as a batch process. This work provides insight into continuous column extraction. Different waste cooking oils were used to produce biodiesel via transesterification with methanol, and the selective solvent for purification was DES choline chloride–ethylene glycol (1:2.5, mol.). A laboratory Karr column at different pulsation frequencies and DES to biodiesel mass ratio was used for extraction. Plate material (steel and 3D printed PETG) and geometry influence on the efficiency of extraction were investigated. Contact angle measurement was used to measure the surface free energy of steel and PETG and the spreading ability of biodiesel and DESs on both materials. Extraction efficiency was analyzed by several analytical techniques. Higher efficiency was observed with steel plates of a triangular pitch hole arrangement. Increasing the mixing intensity and DES to biodiesel mass ratio further increased the efficiency of extraction.
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(This article belongs to the Special Issue Application of Deep Eutectic Solvents in Green Separation Chemistry)
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An Evaluation of the Relationship between Membrane Properties and the Fouling Mechanism Based on a Blocking Filtration Model
by
Nobuyuki Katagiri, Takehiro Uchida, Hironori Takahashi and Eiji Iritani
Separations 2024, 11(3), 70; https://doi.org/10.3390/separations11030070 - 24 Feb 2024
Abstract
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Microfiltration plays an increasingly important role in various fields. Consequently, elucidating the mechanism of membrane fouling has emerged as a pivotal issue that needs to be resolved. In this study, a blocking filtration model was employed to evaluate the effects of membrane properties
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Microfiltration plays an increasingly important role in various fields. Consequently, elucidating the mechanism of membrane fouling has emerged as a pivotal issue that needs to be resolved. In this study, a blocking filtration model was employed to evaluate the effects of membrane properties on the fouling mechanism during the microfiltration of representative polysaccharides, namely sodium alginate, pectin, and xanthan gum. Microfiltration membranes composed of hydrophilic and hydrophobic PVDF, mixed cellulose ester, as well as hydrophilic and hydrophobic PTFE were used as filter media. The flux decline behavior was significantly affected by the membrane properties, with hydrophilic membranes exhibiting a slower decrease in filtration rate. The model analysis revealed a correlation between the blocking characteristic values and the membrane properties. Although the blocking index n showed membrane material dependence, the values of this parameter remained consistent across various filtration conditions, including the wettability of the membrane surface, solute concentration, and pressure (pectin: n = 1.86, 1.85, 1.50, and 1.50 for hydrophilic PVDF, hydrophobic PVDF, hydrophilic PTFE, and hydrophobic PTFE, respectively). The resistance coefficient k was influenced by the characteristics of the membrane surface; the k values of the hydrophobic membranes were higher than those of the hydrophilic ones (pectin: k = 0.00084, 0.00725, 0.00714, and 0.0384 s1−n/cm2−n for hydrophilic PVDF, hydrophobic PVDF, hydrophilic PTFE, and hydrophobic PTFE, respectively). The model calculations, based on the values of n and k, demonstrated a relatively good agreement with the experimental data.
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Features and Advantages of the Recurrent Approximation of Retention Times in Reversed-Phase High-Performance Liquid Chromatography
by
Igor G. Zenkevich and Abdennour Derouiche
Separations 2024, 11(3), 69; https://doi.org/10.3390/separations11030069 - 24 Feb 2024
Abstract
Background: Recurrent approximation of retention parameters in reversed-phase HPLC is effective for revealing anomalies that are otherwise difficult to detect, namely, the reversible hydration of analytes. This was demonstrated previously for restricted sets of analytes with acetonitrile–water eluents. Expanding the number of
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Background: Recurrent approximation of retention parameters in reversed-phase HPLC is effective for revealing anomalies that are otherwise difficult to detect, namely, the reversible hydration of analytes. This was demonstrated previously for restricted sets of analytes with acetonitrile–water eluents. Expanding the number of analytes and eluents seems to be a topical problem. Two kinds of derivatives of aromatic carbonyl compounds were characterized: unsubstituted hydrazones and oximes. Methods: If analyte demonstrates no anomalies in dependences of retention times vs. concentration of organic modifier, the recurrent approximations of these dependences are linear. To explain the features of recurrent approximations, the numerical experiments were proposed and considered. The artificial shifting of one, two, or more points allows for the modeling the different kinds of deviations of approximations from linearity. Results: It was shown that hydrazones are the class of analytes having no anomalies of retention parameters. On the contrary, several anomalies were detected for oximes. Downward deviations of points in the plots of recurrent approximations of retention times are the signs of reversible hydration. This effect for methanol–water eluents was detected for the first time. Some of oximes underwent hydrolysis. Conclusions: Recurrent approximation of retention times allows detecting chemical transformations of analytes during RP HPLC analysis.
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(This article belongs to the Section Chromatographic Separations)
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