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22 pages, 9737 KiB

Open AccessArticle

Comprehensive Profiling of Illicit Amphetamines Seized in Poland: Insights from Gas Chromatography–Mass Spectrometry and Chemometric Analysis

by Anna Czyż, Katarzyna Pawlak, Emilia Waraksa and Tomasz Bieńkowski

Molecules 2025, 30(3), 579; https://doi.org/10.3390/molecules30030579 - 27 Jan 2025

Viewed by 1064

Abstract

The illicit production and distribution of amphetamines present significant challenges to public health and law enforcement, particularly in Europe, where these substances dominate the stimulant market. This study aimed to profile amphetamines consumed within a Polish community by employing gas chromatography–mass spectrometry (GC-MS) [...] Read more.

The illicit production and distribution of amphetamines present significant challenges to public health and law enforcement, particularly in Europe, where these substances dominate the stimulant market. This study aimed to profile amphetamines consumed within a Polish community by employing gas chromatography–mass spectrometry (GC-MS) and chemometric techniques to analyze their chemical composition and associated impurities. The optimized GC-MS methodology facilitated the identification of synthesis markers, precursor origins, and distribution patterns. Impurity profiling provided critical insights into regional production trends, including the use of specific precursors and adulterants. Chemometric analysis further enabled the classification of samples into distinct groups, shedding light on their origins and distribution chains. These findings underscore the potential of extending amphetamine profiling to include distribution-related compounds, offering a powerful tool for tracking production trends and enhancing forensic investigations in the fight against drug trafficking. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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18 pages, 10306 KiB

Open AccessArticle

Influence of Solvent Relative Permittivity in Swab Spray Mass Spectrometry

by Thomas Michael Muggli and Stefan Schürch

Molecules 2024, 29(17), 4274; https://doi.org/10.3390/molecules29174274 - 9 Sep 2024

Cited by 2 | Viewed by 1180

Abstract

The influence of solvent properties on ion generation by swab spray ionization was investigated. The ability of a variety of solvents of different relative permittivity, surface tension, and viscosity to form a stable and reproducible electrospray was examined. It is demonstrated that in [...] Read more.

The influence of solvent properties on ion generation by swab spray ionization was investigated. The ability of a variety of solvents of different relative permittivity, surface tension, and viscosity to form a stable and reproducible electrospray was examined. It is demonstrated that in swab spray ionization, a crucial balance between solvent composition, applied potential, and the solvent flow fed to the swab head must be maintained. The solvent composition was found to significantly affect the shape of the Taylor cone and the emerging cone jet, which eventually have an impact on the resulting ion yield. The results indicate that the relative permittivity of solvents measured under standard conditions is the main factor governing jet shaping, and consequently, the ionization efficacy. Short jets, which are required for maximum ion yield, were observed for solvents with relative permittivity ε_r higher than 25. Solvents exhibiting lower relative permittivity required the addition of 20% to 60% methanol to limit the jet length and to avoid the ineffective dripping pulsation. The observed effects were compared to conventional electrospray ionization and paper spray ionization. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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17 pages, 2983 KiB

Open AccessArticle

Chemical and Thermal Characteristics of PEF-Pretreated Strawberries Dried by Various Methods

by Aleksandra Matys, Małgorzata Nowacka, Dorota Witrowa-Rajchert and Artur Wiktor

Molecules 2024, 29(16), 3924; https://doi.org/10.3390/molecules29163924 - 20 Aug 2024

Cited by 1 | Viewed by 1111

Abstract

By increasing the permeability of the cell membrane of the treated material, pulsed electric fields (PEF) enhance the internal transport of various chemical substances. Changing the distribution of these components can modify the chemical and thermal properties of the given material. This study [...] Read more.

By increasing the permeability of the cell membrane of the treated material, pulsed electric fields (PEF) enhance the internal transport of various chemical substances. Changing the distribution of these components can modify the chemical and thermal properties of the given material. This study aimed to analyze the impact of PEF (1 kV/cm; 1 and 4 kJ/kg) applied to strawberries prior to drying by various methods (convective, infrared-convective, microwave-convective, and vacuum) on the chemical and thermal properties of the obtained dried materials (sugars content, total phenolic content, and antioxidant capacity (ABTS and DPPH assays); thermal properties (TGA and DSC); and molecular composition (FTIR)). PEF could have induced and/or enhanced sucrose inversion because, compared to untreated samples, PEF-pretreated samples were characterized by a lower share of sucrose in the total sugar content but a higher share of glucose and fructose. Reduced exposure to oxygen and decreased drying temperature during vacuum drying led to obtaining dried strawberries with the highest content of antioxidant compounds, which are sensitive to these factors. All PEF-pretreated dried strawberries exhibited a lower glass transition temperature (T_g) than the untreated samples, which confirms the increased mobility of the system after the application of an electric field. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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17 pages, 2229 KiB

Open AccessArticle

Elemental Profiling for the Detection of Food Mixtures: A Proof of Principle Study on the Detection of Mixed Walnut Origins Using Measured and Calculated Data

by Marie-Sophie Müller, Esra Erçetin, Lina Cvancar, Marie Oest and Markus Fischer

Molecules 2024, 29(14), 3350; https://doi.org/10.3390/molecules29143350 - 17 Jul 2024

Cited by 4 | Viewed by 1010

Abstract

Element profiling is a powerful tool for detecting fraud related to claims of geographical origin. However, these methods must be continuously developed, as mixtures of different origins in particular offer great potential for adulteration. This study is a proof of principle to determine [...] Read more.

Element profiling is a powerful tool for detecting fraud related to claims of geographical origin. However, these methods must be continuously developed, as mixtures of different origins in particular offer great potential for adulteration. This study is a proof of principle to determine whether elemental profiling is suitable for detecting mixtures of the same food but from different origins and whether calculated data from walnut mixtures could help to reduce the measurement burden. The calculated data used in this study were generated based on measurements of authentic, unadulterated samples. Five different classification models and three regression models were applied in five different evaluation approaches to detect adulteration or even distinguish between adulteration levels (10% to 90%). To validate the method, 270 mixtures of walnuts from different origins were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Depending on the evaluation approach, different characteristics were observed in mixtures when comparing the calculated and measured data. Based on the measured data, it was possible to detect admixtures with an accuracy of 100%, even at low levels of adulteration (20%), depending on the country. However, calculated data can only contribute to the detection of adulterated walnut samples in exceptional cases. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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12 pages, 1620 KiB

Open AccessArticle

Green HPLC Enantioseparation of Chemopreventive Chiral Isothiocyanates Homologs on an Immobilized Chiral Stationary Phase Based on Amylose tris-[(S)-α-Methylbenzylcarbamate]

by Francesca Romana Mammone, Alessia Panusa, Roberta Risoluti and Roberto Cirilli

Molecules 2024, 29(12), 2895; https://doi.org/10.3390/molecules29122895 - 18 Jun 2024

Cited by 2 | Viewed by 1211

Abstract

Sulforaphane is a chiral phytochemical with chemopreventive properties. The presence of a stereogenic sulfur atom is responsible for the chirality of the natural isothiocyanate. The key role of sulfur chirality in biological activity is underscored by studies of the efficacy of individual enantiomers [...] Read more.

Sulforaphane is a chiral phytochemical with chemopreventive properties. The presence of a stereogenic sulfur atom is responsible for the chirality of the natural isothiocyanate. The key role of sulfur chirality in biological activity is underscored by studies of the efficacy of individual enantiomers as chemoprotective agents. The predominant native (R) enantiomer is active, whereas the (S) antipode is inactive or has little or no biological activity. Here we provide an enantioselective high-performance liquid chromatography (HPLC) protocol for the direct and complete resolution of sulforaphane and its chiral natural homologs with different aliphatic chain lengths between the sulfinyl sulfur and isothiocyanate group, namely iberin, alyssin, and hesperin. The chromatographic separations were carried out on the immobilized-type CHIRALPAK IH-3 chiral stationary phase with amylose tris-[(S)-methylbenzylcarbamate] as a chiral selector. The effects of different mobile phases consisting of pure alcoholic solvents and hydroalcoholic mixtures on enantiomer retention and enantioselectivity were carefully investigated. Simple and environmentally friendly enantioselective conditions for the resolution of all chiral ITCs were found. In particular, pure ethanol and highly aqueous mobile phases gave excellent enantioseparations. The retention factors of the enantiomers were recorded as the water content in the aqueous-organic modifier (methanol, ethanol, or acetonitrile) mobile phases progressively varied. U-shaped retention maps were generated, indicating a dual and competitive hydrophilic interaction liquid chromatography (HILIC) and reversed-phase liquid chromatography retention mechanism on the CHIRALPAK IH-3 chiral stationary phase. Finally, experimental chiroptical studies performed in ethanol solution showed that the (R) enantiomers were eluted before the (S) counterpart under all eluent conditions investigated. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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15 pages, 1969 KiB

Open AccessArticle

Exploring the Impact of Various Wooden Barrels on the Aromatic Profile of Aceto Balsamico Tradizionale di Modena by Means of Principal Component Analysis

by Caterina Durante, Lorenzo Morelli, Veronica D’Eusanio, Lorenzo Tassi and Andrea Marchetti

Molecules 2024, 29(11), 2647; https://doi.org/10.3390/molecules29112647 - 4 Jun 2024

Viewed by 868

Abstract

The study examines the unique production process of Aceto Balsamico Tradizionale di Modena PDO (ABTM), emphasizing its complex phases and the impact of raw materials and artisanal skill on its flavor characteristics. Analytical tests focused on the volatile composition of vinegars from different [...] Read more.

The study examines the unique production process of Aceto Balsamico Tradizionale di Modena PDO (ABTM), emphasizing its complex phases and the impact of raw materials and artisanal skill on its flavor characteristics. Analytical tests focused on the volatile composition of vinegars from different wood barrels at different aging stages, using solid-phase micro-extraction (SPME) coupled with gas chromatography, either with mass spectrometry (GC/MS) or flame ionization detector (FID). Multivariate analysis, including principal component analysis (PCA), was employed to investigate the presence of peculiarities among the volatile profiles of samples of different barrel origin. The research focuses on characterizing the volatile composition of vinegars sourced from individual wood barrels, such as Cherry, Chestnut, Mulberry, Juniper, and Oak. Although it was not possible to identify molecules directly connected to the woody essence, some similarities emerged between vinegar samples from mulberry and cherry barrels and between those of juniper and oak. The former group is characterized by analytes with high molecular weights, such as furfural and esters, while the latter group shows more intense peaks for ethyl benzoate. Moreover, ethyl benzoate appears to predominantly influence samples from chestnut barrels. Due to the highly complex production process of ABTM, where each battery is influenced by several factors, this study’s findings are specific to the current experimental conditions. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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12 pages, 421 KiB

Open AccessArticle

Chemical Profile and Healthy Properties of Sicilian Diplotaxis harra subsp. crassifolia (Raf.) Maire

by Natale Badalamenti, Assunta Napolitano, Maurizio Bruno, Roberta Pino, Rosa Tundis, Vincenzo Ilardi, Monica Rosa Loizzo and Sonia Piacente

Molecules 2024, 29(11), 2450; https://doi.org/10.3390/molecules29112450 - 23 May 2024

Viewed by 1124

Abstract

This study was aimed at investigating the phytochemical profile and bioactivity of Diplotaxis harra subsp. crassifolia (Brassicaceae), a species from central–southern Sicily (Italy), where it is consumed as a salad. For this purpose, LC–ESI/HRMSⁿ analysis of the ethanolic extract was performed, highlighting [...] Read more.

This study was aimed at investigating the phytochemical profile and bioactivity of Diplotaxis harra subsp. crassifolia (Brassicaceae), a species from central–southern Sicily (Italy), where it is consumed as a salad. For this purpose, LC–ESI/HRMSⁿ analysis of the ethanolic extract was performed, highlighting the occurrence, along with flavonoids, hydroxycinnamic acid derivatives, and oxylipins, of sulfated secondary metabolites, including glucosinolates and various sulfooxy derivatives (e.g., C13 nor-isoprenoids, hydroxyphenyl, and hydroxybenzoic acid derivatives), most of which were never reported before in the Brassicaeae family or in the Diplotaxis genus. Following ethnomedicinal information regarding this species used for the treatment of various pathologies such as diabetes and hypercholesterolemia, D. harra ethanolic extract was evaluated for its antioxidant potential using different in vitro tests such as 2,2-diphenyl-1-picrylhydrazyl, 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), Ferric Reducing Ability Power, and β-carotene bleaching tests. The inhibitory activity of carbohydrate-hydrolyzing enzymes (α-amylase and α-glucosidase) and pancreatic lipase was also assessed. In the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid assay, an IC₅₀ value comparable to the positive control ascorbic acid (2.87 vs. 1.70 μg/mL, respectively) was obtained. The wild-wall rocket salad extract showed a significant α-amylase inhibitory effect. Obtained results indicate that Sicilian wild-wall rocket contains phytochemicals that can prevent hyperglycemia, hyperlipidemia, and obesity. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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20 pages, 1798 KiB

Open AccessArticle

Starch from Unripe Apples (Malus domestica Borkh) as an Alternative for Application in the Food Industry

by Dorota Gumul, Jarosław Korus, Magdalena Orczykowska, Justyna Rosicka-Kaczmarek, Joanna Oracz and Anna Areczuk

Molecules 2024, 29(8), 1707; https://doi.org/10.3390/molecules29081707 - 10 Apr 2024

Viewed by 1370

Abstract

This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics [...] Read more.

This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics were studied. The starches differed significantly in ash, phosphorus, and protein content. The water-binding capacity at temperatures of 25–65 °C was similar, while differences of 20% appeared at higher temperatures. In contrast, a significant difference was found in the solubility of the two starches in the temperature range of 25–75 °C. The study showed that apple starches have a relatively low tendency to retrograde, with the enthalpy of gelatinization for starch from the Oliwka variety being 40% higher than that from the Pyros variety. However, the starches differed in the hardness of the gels formed, i.e., one variety formed soft gels with an internal structure resistant to external forces, while the other formed hard gels. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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20 pages, 11990 KiB

Open AccessArticle

Interactions between Damaged Hair Keratin and Juglone as a Possible Restoring Agent: A Vibrational and Scanning Electron Microscopy Study

by Michele Di Foggia, Paola Taddei, Carla Boga, Benedetta Nocentini and Gabriele Micheletti

Molecules 2024, 29(2), 320; https://doi.org/10.3390/molecules29020320 - 9 Jan 2024

Cited by 1 | Viewed by 2479

Abstract

Juglone, a quinonic compound present in walnut extracts, was proposed as a restoring agent for hair keratin treated with permanent or discoloration processes. The proposed mechanism of restoration by juglone involves the formation of a Michael adduct between the quinone and the thiol [...] Read more.

Juglone, a quinonic compound present in walnut extracts, was proposed as a restoring agent for hair keratin treated with permanent or discoloration processes. The proposed mechanism of restoration by juglone involves the formation of a Michael adduct between the quinone and the thiol moieties of cysteine residues. To this purpose, the first part of the present paper involved the spectroscopic study of the product of the reaction between juglone and N-acetyl-L-cysteine as a model compound. IR spectroscopy and Scanning Electron Microscopy (SEM) monitored the chemical and morphological variations induced by applying juglone to hair keratin. In order to simulate the most common hair treatments (i.e., permanent and discoloration), juglone was applied to hair that had been previously treated with a reducing agent, i.e., methyl thioglycolate (MT) or with bleaching agents (based on hydrogen peroxide and persulfates) followed by sodium hydrogen sulfite. IR spectroscopy allowed us to monitor the formation of Michael adducts between juglone and cysteine residues: the Michael adducts’ content was related to the cysteine content of the samples. In fact, MT and sodium hydrogen sulfite favored the reduction of the disulfide bonds and increased the content of free cysteine residues, which can react with juglone. SEM analyses confirmed the trend observed by IR spectroscopy since hair samples treated with juglone adopted a more regular hair surface and more imbricated scales, thus supporting the possible use of juglone as a restoring agent for damaged hair keratins. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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15 pages, 3886 KiB

Open AccessArticle

Electron Beam Processing as a Promising Tool to Decontaminate Polymers Containing Brominated Flame Retardants

by Rachida Khadidja Benmammar, Venkateswara Rao Mundlapati, Zohra Bouberka, Ana Barrera, Jean-Noël Staelens, Jean-François Tahon, Michael Ziskind, Yvain Carpentier, Cristian Focsa, Philippe Supiot, Corinne Foissac and Ulrich Maschke

Molecules 2023, 28(23), 7753; https://doi.org/10.3390/molecules28237753 - 24 Nov 2023

Cited by 3 | Viewed by 2356

Abstract

Electron Beam (EB) irradiation was utilized to decontaminate model systems of industrial polymers that contain a brominated flame retardant (BFR). Acrylonitrile-butadiene-styrene (ABS) and Polycarbonate (PC) are two types of polymers commonly found in Waste Electrical and Electronic Equipment (WEEE). In this study, these [...] Read more.

Electron Beam (EB) irradiation was utilized to decontaminate model systems of industrial polymers that contain a brominated flame retardant (BFR). Acrylonitrile-butadiene-styrene (ABS) and Polycarbonate (PC) are two types of polymers commonly found in Waste Electrical and Electronic Equipment (WEEE). In this study, these polymers were exposed to EB irradiation to degrade DecaBromoDiphenylEther (DBDE), one of the most toxic BFRs. Fourier-transform infrared spectroscopy analysis demonstrated an 87% degradation rate of DBDE for the ABS-DBDE system and 91% for the PC-DBDE system following an 1800 kGy irradiation dose. Thermal analysis using Differential Scanning Calorimetry revealed the presence of crosslinking in ABS and a minor reduction in the glass transition temperature of PC after EB processing. Polymers exhibited thermal stability after photolysis, as indicated by thermogravimetric analysis. In summary, EB irradiation had no impact on the overall thermal properties of both polymers. High-resolution mass spectrometry analysis has confirmed the debromination of both ABS-DBDE and PC-DBDE systems. Therefore, the results obtained are promising and could offer an alternative approach for removing bromine and other additives from plastic E-waste. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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14 pages, 6089 KiB

Open AccessArticle

Myo-Inositol, Scyllo-Inositol, and Other Minor Carbohydrates as Authenticity Markers for the Control of Italian Bulk, Concentrate, and Rectified Grape Must

by Mauro Paolini, Matteo Perini, Letizia Allari, Loris Tonidandel, Fabio Finato, Katia Guardini and Roberto Larcher

Molecules 2023, 28(8), 3609; https://doi.org/10.3390/molecules28083609 - 20 Apr 2023

Cited by 3 | Viewed by 1979

Abstract

Myo-inositol polyalcohol is a characteristic component of natural and concentrated grape musts (CMs), and Regulation (EU) no. 1308/2013 prescribes its presence as a marker of the authenticity of rectified concentrated must (RCM). Other polyalcohols besides myo-inositol, such as scyllo-inositol or [...] Read more.

Myo-inositol polyalcohol is a characteristic component of natural and concentrated grape musts (CMs), and Regulation (EU) no. 1308/2013 prescribes its presence as a marker of the authenticity of rectified concentrated must (RCM). Other polyalcohols besides myo-inositol, such as scyllo-inositol or minor sugars, could be considered authenticity markers, but an extensive search in the literature yielded no exhaustively investigated study of their concentration variability in genuine products. The aim of this study was to create an extensive national data bank of minor carbohydrates profiles and investigate the impact of the geographical origin and the different vintages on the concentration of these compounds; to this end, 450 authentic Italian grape musts of different varieties were sampled and analyzed during the harvest season in 2019, 2020, and 2021. The grape musts from the Italian wine-growing areas CII and CIIIb had myo- and scyllo-inositol contents always higher than 756 and 39 mg/kg of sugar, respectively. Conversely, also considering other mono- and disaccharides, sucrose, sorbitol, lactose, maltose, and isomaltose showed contents always lower than 534, 1207, 390, 2222, and 1639 mg/kg of sugar, respectively. The general applicability to the CM and RCM of the proposed authenticity thresholds, established in the must, was demonstrated by studying the influence of must concentration on the myo- and scyllo-inositol content. Inter-laboratory comparison experiments were also conducted to harmonize and characterize laboratory methods and validate the analytical dataset. Based on the obtained results, the text of the EU legislation (Reg. (EU) 1308/2013), which defines the characteristics of the must and the CRM product, should be revised. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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25 pages, 7420 KiB

Open AccessArticle

Vibrational Study on the Structure, Bioactivity, and Silver Adsorption of Silk Fibroin Fibers Grafted with Methacrylonitrile

by Michele Di Foggia, Masuhiro Tsukada and Paola Taddei

Molecules 2023, 28(6), 2551; https://doi.org/10.3390/molecules28062551 - 10 Mar 2023

Cited by 9 | Viewed by 2297

Abstract

Natural fibers have received increasing attention as starting materials for innovative applications in many research fields, from biomedicine to engineering. Bombyx mori silk fibroin has become a material of choice in the development of many biomedical devices. Grafting represents a good strategy to [...] Read more.

Natural fibers have received increasing attention as starting materials for innovative applications in many research fields, from biomedicine to engineering. Bombyx mori silk fibroin has become a material of choice in the development of many biomedical devices. Grafting represents a good strategy to improve the material properties according to the desired function. In the present study, Bombyx mori silk fibroin fibers were grafted with methacrylonitrile (MAN) with different weight gains. The potential interest in biomedical applications of MAN functionalization relies on the presence of the nitrile group, which is an acceptor of H bonds and can bind metals. IR and Raman spectroscopy were used to characterize the grafted samples and the possible structural changes induced by grafting. Afterward, the same techniques were used to study the bioactivity (i.e., the calcium phosphate nucleation ability) of MAN-grafted silk fibroins after ageing in simulated body fluid (SBF) for possible application in bone tissue engineering, and their interaction with Ag⁺ ions, for the development of biomaterials with enhanced anti-microbial properties. MAN was found to efficiently polymerize on silk fibroin through polar amino acids (i.e., serine and tryptophan), inducing an enrichment in silk fibroin-ordered domains. IR spectroscopy allowed us to detect the nucleation of a thin calcium phosphate layer and the uptake of Ag⁺ ions through the nitrile group, which may foster the application of these grafted materials in biomedical applications. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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13 pages, 1907 KiB

Open AccessArticle

Recycling of Plastics from E-Waste via Photodegradation in a Low-Pressure Reactor: The Case of Decabromodiphenyl Ether Dispersed in Poly(acrylonitrile-butadiene-styrene) and Poly(carbonate)

by Hussam Aldoori, Zohra Bouberka, Hervé Feuchter, Skander Khelifi, Franck Poutch, Loic Brison, Fouad Laoutid, Stijn Steuperaert, Corinne Foissac, Philippe Supiot, Christian Malas and Ulrich Maschke

Molecules 2023, 28(6), 2491; https://doi.org/10.3390/molecules28062491 - 8 Mar 2023

Cited by 4 | Viewed by 2485

Abstract

Recycling of plastic waste from electrical and electronic equipment (EEE), containing brominated flame retardants (BFR) remains difficult due to the increasingly stringent regulations on their handling and recovery. This report deals with photodegradation in a low-pressure reactor applying UV-visible light on Decabromodiphenyl ether [...] Read more.

Recycling of plastic waste from electrical and electronic equipment (EEE), containing brominated flame retardants (BFR) remains difficult due to the increasingly stringent regulations on their handling and recovery. This report deals with photodegradation in a low-pressure reactor applying UV-visible light on Decabromodiphenyl ether (DBDE or BDE-209) randomly dispersed in commercially available Poly(acrylonitrile-butadiene-styrene) (ABS) and Poly(carbonate) (PC). The aim of this study is to investigate the possibility of decomposing a BFR in plastic waste from EEE while maintaining the specifications of the polymeric materials in order to allow for their recycling. The photodegradation of the extracted BFR was monitored using infrared spectroscopy and gas chromatography coupled with mass spectroscopy. DBDE underwent rapid photodegradation during the first minutes of exposure to UV-visible light and reached degradation yields superior to 90% after 15 min of irradiation. The evaluation of polymer properties (ABS and PC) after irradiation revealed superficial crosslinking effects, which were slightly accelerated in the presence of DBDE. However, the use of a low-pressure reactor avoids large photooxidation and allowed to maintain the thermal and structural properties of the virgin polymers. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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12 pages, 4073 KiB

Open AccessArticle

TG-DSC and TG-FTIR Studies of Annelated Triazinylacetic Acid Ethyl Esters—Potential Anticancer Agents

by Agnieszka Ostasz, Renata Łyszczek, Krzysztof Sztanke and Małgorzata Sztanke

Molecules 2023, 28(4), 1735; https://doi.org/10.3390/molecules28041735 - 11 Feb 2023

Cited by 6 | Viewed by 1940

Abstract

To avoid problems associated with the storage and processing of newly developed potential medicines, there is a need to carry out thermal studies in the preclinical phase of drug development. The thermal behaviour and decomposition pathway of a whole novel class of patented [...] Read more.

To avoid problems associated with the storage and processing of newly developed potential medicines, there is a need to carry out thermal studies in the preclinical phase of drug development. The thermal behaviour and decomposition pathway of a whole novel class of patented potential molecular pharmaceutics, i.e., ethyl 2-[4-oxo-8-(R-phenyl)-4,6,7,8-tetrahydroimidazo[2,1-c][1,2,4]triazin-3-yl]acetates (1–6) were reported for the first time in inert and oxidative atmospheres. The experiments were conducted with the use of simultaneous thermogravimetry/differential scanning calorimetry (TG-DSC) and simultaneous thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR). The decomposition pathways of compounds 1–6 were found to be different under oxidative and inert conditions. It was proven that the investigated molecules reveal higher thermal stability under a synthetic air atmosphere than under a nitrogen atmosphere, and their decomposition is preceded by the melting process. Among all the investigated compounds, only the meta-chloro derivative (4) was found to exhibit interesting polymorphic behaviour at a low heating rate (10 °C min⁻¹). It was proven that the oxidative decomposition process of the studied molecules proceeds in three overlapping stages accompanied by strong exothermic effects. Additionally, it was concluded that the title compounds were stable up to a temperature of 195–216 °C in an atmosphere of synthetic air, and their thermal stability decreased in the order of R at the benzene ring: 4-CH₃ > 3,4-Cl₂ > 4-Cl > H > 2-OCH₃ > 3-Cl. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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10 pages, 936 KiB

Open AccessArticle

Unbiased Determination of Adsorption Isotherms by Inverse Method in Liquid Chromatography

by Szabolcs Horváth, Diána Lukács, Evelin Farsang and Krisztián Horváth

Molecules 2023, 28(3), 1031; https://doi.org/10.3390/molecules28031031 - 19 Jan 2023

Cited by 5 | Viewed by 2767

Abstract

The Inverse Method is a widely used technique for the determination of adsorption isotherms in liquid chromatography. In this method, isotherm is determined from the overloaded peak profile of the component by the iterative solution of the mass balance equation of liquid chromatography. [...] Read more.

The Inverse Method is a widely used technique for the determination of adsorption isotherms in liquid chromatography. In this method, isotherm is determined from the overloaded peak profile of the component by the iterative solution of the mass balance equation of liquid chromatography. Successful use of this method requires a prior assumption of equation of isotherm (Langmuir, BET etc.). In this work, we have developed an inverse method that gives results of similar accuracy to the frontal analysis without assuming the equation of the isotherm. The oversaturated peaks were calculated using a spline fitted to data points instead of the derivative of the isotherm. The distribution of the isotherm points were optimized for minimizing the difference between the measured and calculated overloaded peaks. The accuracy of the developed method was verified with synthetic benchmark peaks and by the determination of isotherm of buthyl-benzoate under real conditions. The results confirmed that the accuracy of the developed method is similar to that of Frontal Analysis. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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21 pages, 7222 KiB

Open AccessArticle

The Determination of Cannabinoids in Urine Samples Using Microextraction by Packed Sorbent and Gas Chromatography-Mass Spectrometry

by Luana M. Rosendo, Tiago Rosado, Patrik Oliveira, Ana Y. Simão, Cláudia Margalho, Suzel Costa, Luís A. Passarinha, Mário Barroso and Eugenia Gallardo

Molecules 2022, 27(17), 5503; https://doi.org/10.3390/molecules27175503 - 27 Aug 2022

Cited by 13 | Viewed by 3384

Abstract

Cannabis is the most consumed illicit drug worldwide, and its legal status is a source of concern. This study proposes a rapid procedure for the simultaneous quantification of Δ⁹-tetrahydrocannabinol (THC), 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH), cannabidiol (CBD), and [...] Read more.

Cannabis is the most consumed illicit drug worldwide, and its legal status is a source of concern. This study proposes a rapid procedure for the simultaneous quantification of Δ⁹-tetrahydrocannabinol (THC), 11-hydroxy-Δ⁹-tetrahydrocannabinol (11-OH-THC), 11-nor-9-carboxy-Δ⁹-tetrahydrocannabinol (THC-COOH), cannabidiol (CBD), and cannabinol (CBN) in urine samples. Microextraction by packed sorbent (MEPS) was used to pre-concentrate the analytes, which were detected by gas chromatography–mass spectrometry. The procedure was previously optimized, and the final conditions were: conditioning with 50 µL methanol and 50 µL of water, sample load with two draw–eject cycles, and washing with 310 µL of 0.1% formic acid in water with 5% isopropanol; the elution was made with 35 µL of 0.1% ammonium hydroxide in methanol. This fast extraction procedure allowed quantification in the ranges of 1–400 ng/mL for THC and CBD, 5–400 ng/mL for CBN and 11-OH-THC, and 10–400 ng/mL for THC-COOH with coefficients of determination higher than 0.99. The limits of quantification and detection were between 1 and 10 ng/mL using 0.25 mL of sample. The extraction efficiencies varied between 26 and 85%. This analytical method is the first allowing the for determination of cannabinoids in urine samples using MEPS, a fast, simple, and low-cost alternative to conventional techniques. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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29 pages, 847 KiB

Open AccessReview

Determination of Antiepileptics in Biological Samples—A Review

by João Martinho, Ana Y. Simão, Mário Barroso, Eugenia Gallardo and Tiago Rosado

Molecules 2024, 29(19), 4679; https://doi.org/10.3390/molecules29194679 - 2 Oct 2024

Cited by 1 | Viewed by 1494

Abstract

Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent [...] Read more.

Epilepsy remains a disease that affects many people around the world. With the development of new drugs to treat this condition, the importance of therapeutic drug monitoring continues to rise and remains a challenge for the medical community. This review article explores recent advances in the detection of antiepileptic drugs across various sample types commonly used for drug monitoring, with a focus on their applications and impact. Some of these new methods have proven to be simpler, greener, and faster, making them easier to apply in the context of therapeutic drug monitoring. Additionally, besides the classic use of blood and its derivatives, there has been significant research into the application of alternative matrices due to their ease of sample collection and capacity to reflect drug behavior in blood. These advances have contributed to increasing the efficacy of therapeutic drug monitoring while enhancing its accessibility to the population. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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29 pages, 8671 KiB

Open AccessReview

A Critical Review of Analytical Methods for the Quantification of Phthalates Esters in Two Important European Food Products: Olive Oil and Wine

by Flávia Freitas, Maria João Cabrita and Marco Gomes da Silva

Molecules 2023, 28(22), 7628; https://doi.org/10.3390/molecules28227628 - 16 Nov 2023

Cited by 6 | Viewed by 3695

Abstract

Phthalic acid esters (PAEs) are a class of chemicals widely used as plasticizers. These compounds, considered toxic, do not bond to the polymeric matrix of plastic and can, therefore, migrate into the surrounding environment, posing a risk to human health. The primary source [...] Read more.

Phthalic acid esters (PAEs) are a class of chemicals widely used as plasticizers. These compounds, considered toxic, do not bond to the polymeric matrix of plastic and can, therefore, migrate into the surrounding environment, posing a risk to human health. The primary source of human exposure is food, which can become contaminated during cultivation, production, and packaging. Therefore, it is imperative to control and regulate this exposure. This review covers the analytical methods used for their determination in two economically significant products: olive oil and wine. Additionally, it provides a summary and analysis of information regarding the characteristics, toxicity, effects on human health, and current regulations pertaining to PAEs in food. Various approaches for the extraction, purification, and quantification of these analytes are highlighted. Solvent and sorbent-based extraction techniques are reviewed, as are the chromatographic separation and other methods currently applied in the analysis of PAEs in wines and olive oils. The analysis of these contaminants is challenging due to the complexities of the matrices and the widespread presence of PAEs in analytical laboratories, demanding the implementation of appropriate strategies. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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19 pages, 1450 KiB

Open AccessReview

On-Site Detection of Volatile Organic Compounds (VOCs)

by Ruben Epping and Matthias Koch

Molecules 2023, 28(4), 1598; https://doi.org/10.3390/molecules28041598 - 7 Feb 2023

Cited by 73 | Viewed by 12217

Abstract

Volatile organic compounds (VOCs) are of interest in many different fields. Among them are food and fragrance analysis, environmental and atmospheric research, industrial applications, security or medical and life science. In the past, the characterization of these compounds was mostly performed via sample [...] Read more.

Volatile organic compounds (VOCs) are of interest in many different fields. Among them are food and fragrance analysis, environmental and atmospheric research, industrial applications, security or medical and life science. In the past, the characterization of these compounds was mostly performed via sample collection and off-site analysis with gas chromatography coupled to mass spectrometry (GC-MS) as the gold standard. While powerful, this method also has several drawbacks such as being slow, expensive, and demanding on the user. For decades, intense research has been dedicated to find methods for fast VOC analysis on-site with time and spatial resolution. We present the working principles of the most important, utilized, and researched technologies for this purpose and highlight important publications from the last five years. In this overview, non-selective gas sensors, electronic noses, spectroscopic methods, miniaturized gas chromatography, ion mobility spectrometry and direct injection mass spectrometry are covered. The advantages and limitations of the different methods are compared. Finally, we give our outlook into the future progression of this field of research. Full article

(This article belongs to the Special Issue Analytical Chemistry in Europe: Towards Sustainability and Quality of Life)

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