The growth of renewable energy infrastructure highlights the urgent need for sustainable solutions to manage its end-of-life materials, including wind turbine blades (WTBs). These composite materials present significant challenges in recycling due to their complex heterogeneous structure and varied chemical composition. To depolymerize WTB composite materials, a solvolysis process was applied. The resulting chemical products underwent microwave-assisted extraction (MAE), using a mixture of n-hexane and methanol (10:3, v:v). The nonpolar organic phase was subjected to analysis using comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry (GC×GC-ToFMS). On the basis of electron impact ionization mass spectral matching at 70 eV, linear retention index data, and molecular distribution on the two-dimensional space, >110 compounds were putatively identified, mainly composed by aromatic and heteroatom-containing species. To the best of our knowledge, this is the first time that the molecular composition of WTBs has been investigated by MAE-GC×GC–MS.

This study aimed to investigate the content of oxygen heterocyclic compounds, especially coumarin and furocoumarins, in cosmetics products scented with Citrus essential oils. A minor component of the non-volatile fraction of Citrus essences is composed by oxygen heterocyclic compounds, commonly known as coumarins, furocoumarins, and polymethoxyflavones. These molecules show several biological effects on human health. On the other hand, coumarin has the potential to induce skin sensitization and furocoumarins show phototoxic activity. For this reason, several regulation and opinions have been issued concerning the maximum amount of these compounds in cosmetics. Given the regulatory framework, an analytical workflow for extraction and quantification of OHCs from cosmetics is necessary. This research aims to address this challenge by exploring, for the first time, a deep eutectic solvent as eco-friendly alternative for microwave-assisted extraction of these molecules from Citrus-scented creams. A deep eutectic solvent made by chloride and urea, at a molar ratio 1:2, and 20 % of water in weight was selected. Due to the complexity of the sample, a SPE clean-up was mandatory to obtain an extract devoid of interferents. Finally, an HPLC-PDA analytical method was employed allowing the simultaneous separation and quantification of 35 oxygen heterocyclic compounds in less than ten minutes. The analytical workflow here proposed was developed, optimized and validated demonstrating the potentials of deep eutectic solvents and microwaves in this field.

This research investigates the applicability of a microwave-assisted extraction (MAE) methodology using methyl-tert-butyl ether (MTBE) as a one-step organic solvent extraction or in mixture with methanol and water compared to conventional extractions for lipid analysis in food samples. MAE methods were compared in terms of extraction yields and fatty acid (FA) composition to Soxhlet (using n-hexane, MTBE, and diethyl ether) and Matyash (MTBE/CH3OH/H2O, 10/3/2.5, v/v/v), considered gold-standard methodologies for lipid extraction. FAs, derivatized into methyl esters (MEs), were analyzed through a gas chromatography-flame ionization detector. One-way ANOVA and post-hoc Tukey tests were used to identify statistical differences in yields and FAMEs composition, resulting in <10 % with a p < 0.05. Methods using MTBE/CH3OH/H2O showed higher yields but also higher FAMEs variability compared to one-step solvent extraction methods. The extraction techniques showed comparable performance in terms of FAMEs composition. The greenness of the extractions were also evaluated using the AGREEprep metric.

The analysis of mineral oil aromatic hydrocarbons (MOAH) in vegetable oils is currently associated with high uncertainty due to various factors ranging from sample preparation to data interpretation. One significant factor is the coelution of biogenic compounds of terpenic origin with the MOAH fraction during chromatographic analysis. The common purification method is epoxidation, a chemical reaction that changes the polarity of the interferences, allowing their separation from MOAH. However, this reaction is non-selective and can lead to losses of both MOAH and internal standards. This variation is especially noticeable when using epoxidation procedures with higher reaction kinetics, such as those employing performic acid. MOAH losses also vary depending on their composition, which is unpredictable. Furthermore, 2-methylnaphthalene (2MN) and 1,3,5tri-tert-butylbenzene (TBB), which are the common quantification standards, are lost at different rates. As a consequence, the final MOAH quantity will vary both depending on the standard used, and on its initial composition. This work presents a new purification approach based on liquid chromatography fractionation on silica using the same column and eluents as for the usual MOSH/MOAH fractionation. This approach efficiently removes squalene, carotenes, and derivatives, without inducing inconsistent losses between the internal standards and MOAH as epoxidation does. On average, MOAH recovery using this new method was 94% (+/- 8%) in coconut, palm, sunflower, and olive oil, using different MOAH sources and concentrations. Additionally, perspectives are presented regarding the separate analysis and quantification of mono-/diaromatic MOAH and other polyaromatic MOAH. This is of particular interest as these two sub-fractions are associated with different toxicological properties.

Analyzing fatty acids provides key insights into fat composition for industrial applications and their implications for nutrition and health. Typically, fatty acid analysis involves extracting lipids from the matrix and converting them into fatty acid methyl esters (FAME) through a derivatization process before gas chromatography (GC) analysis. Either one-step or two-step procedures can be found in the literature and as official methods. In this work, different methods exploiting microwave-assisted processes were compared with two official methods from the American Oil Chemical Society (AOCS). Especially, two types of microwave-assisted extractions were employed: solvent extraction and extraction with hydrolysis. The extracts were derivatized using either BF3 or a microwave-assisted methanolic hydrogen chloride solution. These combinations of extraction and derivatization methods were compared also with one-step microwave-assisted extraction and derivatization, and two AOCS reference methods, resulting in seven different methods applied to six different food matrices. The performance of the different procedures was compared based on the FAME profile obtained from the comprehensive two-dimensional GC (GC x GC)-FID analysis. Microwave-assisted processes were shown to be effective, yielding results comparable to the official methods in both the one-step and two-step methods. Moreover, it was shown that the BF3 derivatization could be safely replaced with microwave-assisted derivatization with methanolic hydrogen chloride, providing equivalent performances while enhancing operator safety and environmental friendliness. Some discrepancies in the FAMEs profile were highlighted for the sample of oats, the only explicitly requiring acidic hydrolysis for lipid extraction. Further studies are required to understand the reasons behind these differences and develop a suitable modified method. In conclusion, all the methods were evaluated for greenness and blueness with two specific tools: AGREEprep and BAGI.

Non-human primates remain the most useful and reliable pre-clinical model for many human diseases. Primate breath profiles have previously distinguished healthy animals from diseased, including non-human primates. Breath collection is relatively non-invasive, so this motivated us to define a healthy baseline breath profile that could be used in studies evaluating disease, therapies, and vaccines in non-human primates. A pilot study, which enrolled 30 healthy macaques, was conducted. Macaque breath molecules were sampled into a Tedlar bag, concentrated onto a thermal desorption tube, then desorbed and analyzed by comprehensive two-dimensional gas chromatography-time of flight mass spectrometry. These breath samples contained 2,017 features, of which 113 molecules were present in all breath samples. The core breathprint was dominated by aliphatic hydrocarbons, aromatic compounds, and carbonyl compounds. The data were internally validated with additional breath samples from a subset of 19 of these non-human primates. A critical core consisting of 23 highly abundant and invariant molecules was identified as a pragmatic breathprint set, useful for future validation studies in healthy primates.

Aflatoxins pose a major health concern and require strict monitoring in food products. Existing methods rely on hazardous organic solvents for extraction, prompting the development of a greener alternative. This study explores deep eutectic solvents (DESs) for aflatoxin extraction from pistachios, a valuable food product prone to aflatoxin contamination. The proposed method utilizes DES extraction followed by solid-phase extraction cleanup and ultrahigh-performance liquid chromatography coupled with fluorescence detector analysis. Recovery rates ranged from 85.5 to 99.1% for pistachios spiked with 1-8 ng/g aflatoxins, in compliance with EU regulations, with coefficients of variation less than 2.94%. The method demonstrates good sensitivity with limits of detection and quantification in the range of 0.02-0.22 ng/g and 0.05-0.72 ng/g, respectively. Greenness assessment using AGREEPrep and White Analytical Chemistry metrics confirms its environmental sustainability. This approach offers a promising, safer, and more eco-friendly alternative for aflatoxin extraction from complex food matrices like pistachios.

An optimized procedure for extracting and analyzing raw pistachio volatiles was developed through headspace sampling with high-capacity tools and subsequent analysis using comprehensive two-dimensional gas chromatography coupled with mass spectrometry. The examination of 18 pistachio samples belonging to different geographic areas led to the identification of a set of 99 volatile organic compounds (VOCs). Molecules were putatively identified using linear retention index, mass spectra similarity, and two-dimensional plot location. The impact of preprocessing and processing techniques on the aligned data matrix from a set of samples of different geographical origins, after removing contaminants, was evaluated. The combination of scaling with log-transformation, normalization with z-score, and data reduction with random forest machine learning algorithm generated a panel of 16 discriminatory VOC molecules. As a proof of concept, raw pistachios' VOC profile was employed for the first time to tentatively classify them based on their geographical origin.

This work reports the characterization of the lipidic fraction of seven species of marine organisms gathered along the shoreline of the Po Delta Park of Emilia -Romagna Region (Italy) and of the north Adriatic Sea. Two species of oysters ( Crassostrea gigas and Ostrea edulis ), two species of clams ( Chamelea gallina and Ruditapes philippinarum ), one species of mussel ( Mytilus galloprovincialis ), one species of macroalgae ( Ulva rigida ), and one species of spiny dogfish ( Squalus acanthias ) were analyzed to characterize their fatty acids profile and related nutritional value. The lipid fraction was simultaneously extracted and transesterified into fatty acid methyl esters (FAMEs) by using a recently developed one-step microwave-assisted extraction/derivatization (MAED) method. The obtained FAMEs extract was analyzed by a rapid comprehensive multidimensional gas chromatography (GC x GC) method (30 min). The system was equipped with a reverse set of columns (polar x non -polar) connected through a reversed fill/flush flow modulator. The GC x GC system was coupled with a flame-ionization detector (FID) for both qualitative and quantitative purposes. The MAED- GC x GC-FID methodology was suitable in the context of samples containing high percentages of omega -3 PUFA. A total of 82 FAMEs were tentatively identified using standards, literature data, and the two-dimensional plot location. FAME profiles obtained with the proposed approach were comparable with reference methods (AOCS Ce 2b-11), showing no significant differences. Moreover, to determine the food nutritional value of the samples investigated, the most common nutritional indices (index of atherogenicity, index thrombogenicity, hypocholesterolemic/hypercholesterolemic ratio, health-promoting index, unsaturation index, and the fish lipid quality index) were calculated from FAME profiles. Among the samples investigated, Squalus acanthias presented the best nutritional score, while Ruditapes philippinarum had the worst score in 3 out of 6 indices.

Microwave-assisted extraction (MAE) is an important technique in analytical chemistry. It offers several advantages over traditional extraction methods, such as improved extraction efficiency, shorter extraction times, reduced solvent consumption, and enhanced analyte recovery. Using microwaves, heat is directly applied to the sample, leading to rapid and efficient extraction of target compounds by enhancing the solubility and diffusion of the target compounds, thus requiring lower solvent volume. Therefore, MAE can be considered a more environmentally friendly and cost-effective option facilitating the transition toward greener and more sustainable analytical chemistry workflows. This contribution systematically reviews the application of MAE to a selection of target compounds/compounds classes of relevance for food quality and safety assessment. As inclusion criteria, MAE active temperature control and molecularly-resolved characterization of the extracts were considered. Contents include a brief introduction of the principles of operation, available systems characteristics, and key parameters influencing extraction efficiency and selectivity. The application section covers functional food components (e.g., phenols, diterpenes, and carotenoids), lipids, contaminants (e.g., polycyclic aromatic hydrocarbons and mineral oil hydrocarbons), pesticides, veterinary drug residues, and a selection of process contaminants and xenobiotics of relevance for food safety.

A comprehensive chemical characterization of different lipid components, namely fatty acid composition after derivatization in fatty acid methyl esters (FAMEs), triacylglycerols (TAGs), phospholipids (PLs), free fatty acids (FFAs), sterols, carotenoids, tocopherols, and polyphenols in Chia seed oil, obtained by Soxhlet extraction, was reported. Reversed phase liquid chromatography (RP-LC) coupled to UV and mass spectrometry (MS) detectors was employed for carotenoids, polyphenols, and TAGs determination; normal phase-LC in combination with fluorescence detector (FLD) was used for tocopherols analysis; PL and FFA fractions were investigated after a rapid solid phase extraction followed by RP-LC-MS and NanoLC coupled to electron ionization (EI) MS, respectively. Furthermore, gas chromatography (GC)-flame ionization (FID) and MS detectors were used for FAMEs and sterols analysis. Results demonstrated a significant content of bioactive compounds, such as the antioxidant tocopherols (22.88 µg mL−1), and a very high content of essential fatty acids (81.39%), namely α-linolenic (62.16%) and linoleic (19.23%) acids. In addition, for the best of authors knowledge, FFA profile, as well as some carotenoid classes has been elucidated for the first time. The importance of free fatty acids in vegetable matrices is related to the fact that they can be readily involved in metabolic processes or biosynthetic pathways of the plant itself. For a fast and reliable determination of this chemical class, a very innovative and sensitive NanoLC-EI-MS analytical determination was applied.

This review aims to provide a clear overview of the most important analytical development in aflatoxins analysis during the last decade (2013–2022) with a particular focus on nuts and nuts-related products. Aflatoxins (AFs), a group of mycotoxins produced mainly by certain strains of the genus Aspergillus fungi, are known to impose a serious threat to human health. Indeed, AFs are considered carcinogenic to humans, group 1, by the International Agency for Research on Cancer (IARC). Since these toxins can be found in different food commodities, food control organizations worldwide impose maximum levels of AFs for commodities affected by this threat. Thus, they represent a cumbersome issue in terms of quality control, analytical result reliability, and economical losses. It is, therefore, mandatory for food industries to perform analysis on potentially contaminated commodities before the trade. A full perspective of the whole analytical workflow, considering each crucial step during AFs investigation, namely sampling, sample preparation, separation, and detection, will be presented to the reader, focusing on the main challenges related to the topic. A discussion will be primarily held regarding sample preparation methodologies such as partitioning, solid phase extraction (SPE), and immunoaffinity (IA) related methods. This will be followed by an overview of the leading analytical techniques for the detection of aflatoxins, in particular liquid chromatography (LC) coupled to a fluorescence detector (FLD) and/or mass spectrometry (MS). Moreover, the focus on the analytical procedure will not be specific only to traditional methodologies, such as LC, but also to new direct approaches based on imaging and the ability to detect AFs, reducing the need for sample preparation and separative techniques.

One convenient strategy to reduce environmental impact and pollution involves the reuse and revalorization of waste produced by modern society. Nowadays, global plastic production has reached 367 million tons per year and because of their durable nature, their recycling is fundamental for the achievement of the circular economy objective. In closing the loop of plastics, advanced recycling, i.e., the breakdown of plastics into their building blocks and their transformation into valuable secondary raw materials, is a promising management option for post-consumer plastic waste. The most valuable product from advanced recycling is a fluid hydrocarbon stream (or pyrolysis oil) which represents the feedstock for further refinement and processing into new plastics. In this context, gas chromatography is currently playing an important role since it is being used to study the pyrolysis oils, as well as any organic contaminants, and it can be considered a high-resolution separation technique, able to provide the molecular composition of such complex samples. This information significantly helps to tailor the pyrolysis process to produce high-quality feedstocks. In addition, the detection of contaminants (i.e., heteroatom-containing compounds) is crucial to avoid catalytic deterioration and to implement and design further purification processes. The current review highlights the importance of molecular characterization of waste stream products, and particularly the pyrolysis oils obtained from waste plastics. An overview of relevant applications published recently will be provided, and the potential of comprehensive two-dimensional gas chromatography, which represents the natural evolution of gas chromatography into a higher-resolution technique, will be underlined.

This work presents the investigation of the use of heptane as an alternative and less toxic mobile phase to the most used hexane for triacylglycerols (TAGs) analysis in silver ion high-performance liquid chro-matography (Ag +-HPLC). The impact of column temperature (in the 5 & DEG;C-35 & DEG;C range) on the retention and resolution of five pairs of regioisomers relevant for the confectionery industry was investigated using a heptane-based mobile phase modified with acetonitrile (ACN). The retention behaviour was compared for a standard TAG mixture and an interesterified cocoa butter. The temperature effect previously ob-served with hexane-based mobile phases was confirmed for this new system, and it was also observed that the ACN concentration had an important impact on the strength of the temperature effect, with a higher ACN concentration leading to a lesser impact of temperature on the TAGs' elution behaviour. In general, the study allowed to conclude on the equivalence of hexane and heptane for TAGs regioi-somers separation in Ag +-HPLC, independently of the used temperature or the ACN concentration. In addition, the applicability of heptane-based mobile phases for the separation of TAGs regioisomers was demonstrated on three other confectionary fat samples, namely palm olein, interesterified palm olein, and interesterified shea olein. & COPY; 2023 Elsevier B.V. All rights reserved.

The analysis of biological samples of clinical interest has certainly many analytical challenges. Among these, the preparation of samples for the determination of metabolites of interest is of paramount importance to avoid error propagation to the following separation/detection steps, but also to simplify the data elaboration. Sample preparation represents the initial key step for the acquisition of reliable and interpretable information. In this review, we showcase and discuss the most recent sample preparation techniques used for biological samples, limiting to those extracting the small (volatile or volatilizable) metabolites, thus those applications which enable the subsequent GC analysis. Essentially, these include the group of sorbent-based and liquid-based sampling techniques. Dedicated sections devoted to both assisted (i.e., ultrasound, microwave) extraction techniques and chemical derivatizations will also be presented. In the discussion, the importance and recent trends towards the development of green solutions in sample preparation, via automation and miniaturization, are highlighted.

According to the annual production of plastics worldwide, in 2020 about 370 million tons of plastic were produced in the world. Chemical recycling, particularly pyrolysis of plastic wastes, could be a valuable solution to resolve these problems and provide an alternative pathway to produce “recycled” chemical products for the petrochemical industry. Nevertheless, the pyrolysis oils need a detailed characterization before the upgrading test to re-use them to generate new recycled products. Multidimensional gas chromatography coupled with both low- and high-resolution time-of-flight mass spectrometers was employed for a detailed investigation among and within different chemical classes present in bio-plastic oil. The presence of several isomeric species as well as homologs series did not allow a reliable molecular identification, except for a few compounds that showed both MS similarity >800/1000 and retention index within ±20. Indeed, the identification of several isomeric species was assessed by high-resolution mass spectrometry equipped with photoionization interface. This soft ionization mode was an additional filter in the identification step allowing unambiguous identification of analytes not identified by the standard electron ionization mode at 70 eV. The injection method was also optimized using a central composite design to successfully introduce a wide range of carbon number compounds without discrimination of low/high boiling points.

The fatty acid composition of a food product provides information regarding the origin of the product and its overall quality, such as its nutritional value. This work proposes a fast and accurate method for preparing fatty acid methyl esters from a wide variety of food products by using a single-step microwave-assisted extraction and derivatization coupled to reversed fill/flush flow modulation comprehensive two-dimensional gas chromatography (GC×GC) – flame ionization detector (FID) to tentatively identify and quantify the individual fatty acid. The robustness of the GC×GC – FID platform was successfully assessed, as well as the reliability of the entire proposed procedure, assuring repeatability largely below 10%. The enhanced separation obtained by the use of GC×GC allowed for the identification of 81 FAMEs in a single run of 30 min. The fatty acid methyl esters profiles obtained with the proposed microwave-assisted extraction and derivatization were comparable with reference methods from the literature and the American Oil Chemistry Society. This method also proved to be a significant step towards a greener procedure than the reference one when evaluated based on the PrepAGREE metrics that have been recently proposed.

The production of renewable fuels as biodiesel and bio-jet fuel is usually originated by the transformation and processing of oleaginous feedstocks, mainly composed of triacylglycerols. Currently, a significant part of the triacylglycerol production relies on grassy oil crops or other woody oil plants, representing more than 120 million metric tons every year. Considering that the worldwide triacylglycerol demand is expected to rise in the future, alternative routes are necessary to ensure a sustainable biodiesel industry and limit diesel price volatility. In this context, the use of animal fats could be an interesting alternative for biodiesel production as the production of animal byproducts represents nearly 17 million tons per year in the European Union only (2020). Animal fats, however, contain large amounts of no-esterified fatty acids and other oxygen compounds, reducing the yield of biodiesel. Therefore, a specific pretreatment is needed before the trans-esterification process. The setup of such appropriate pretreatments requires detailed upstream characterization of the minor components present in the feedstock. For this purpose, the minor component profile of animal fat was investigated by comprehensive two-dimensional gas chromatography coupled with high-resolution time-of-flight mass spectrometry. This was preceded by an innovative sample fractionation and focalization of these minor components by a preparative liquid chromatographic column method. The overall method permitted to extract different levels of information from the two-dimensional chromatograms, leading to a tentative identification of more than 150 compounds, mainly oxygenated, belonging to different chemical classes.

The advances in hardware components and software tools which characterized the youth of comprehensive two-dimensional gas chromatography (GC × GC) are, as a natural evolution of a novel technique, more and more associated with application-oriented studies covering a wide range of fields. In addition, the high-selectivity and separation power of GC × GC have made the technique one of the most powerful tool for untargeted analysis, especially when coupled with mass spectrometry (MS). It is in this context that this chapter is placed, and specifically in the use of odorant patterns in clinical applications, with these intended as the subset of small volatile metabolites which characterize biological samples. During the last decade, the significance of testing of volatile organic compounds (VOCs) in clinical samples has become high, holding a great potential in offering perspectives of non-invasiveness, availability, and time-effectiveness. Depending on the application, the VOCs emitted from clinical matrices can represent (I) metabolites from the altered physiological status (e.g. cancer), (II) metabolites of the infecting pathogen, (III) reflect the pathogen-induced host responses, or (IV) a combination of both. An initial examination of the analytical challenges which characterize the complexity of the samples will be described. Dedicated sample preparation techniques, as well as multidimensional chromatographic configurations hyphenated to MS will be reported. A collection on milestone papers, sorted by biomedical sample type, will also be discussed, showing the potential of the GC × GC technique in unravelling the complexity of the odorant patterns in clinical application.