Green Extraction Techniques as Advanced Sample Preparation Approaches in Biological, Food, and Environmental Matrices: A Review

Optimizing the Extraction of the Polyphenolic Fraction from Defatted Strawberry Seeds for Tiliroside Isolation Using Accelerated Solvent Extraction Combined with a Box-Behnken Design

Tiliroside is a natural polyphenolic compound with a wide range of biological activity, and defatted strawberry seeds are its rich source. The goal of this study was to optimize accelerated solvent extraction (ASE) conditions, including temperature, solvent composition, and the number of extraction cycles, using Box-Behnken design to maximize the yield of tiliroside. UPLC-DAD-MS was applied to investigate the polyphenolic composition of the extracts, and preparative liquid chromatography (pLC) was used for isolation. All obtained mathematical models generally showed an increase in the efficiency of isolating polyphenolic compounds with an increase in temperature, ethanol content, and the number of extraction cycles. The optimal established ASE conditions for tiliroside were as follows: a temperature of 65 °C, 63% ethanol in water, and four extraction cycles. This allowed for the obtainment of a tiliroside-rich fraction, and the recovery of isolated tiliroside from plant material reached 243.2 mg from 100 g. Our study showed that ASE ensures the isolation of a tiliroside-rich fraction with high effectiveness. Furthermore, defatted strawberry seeds proved to be a convenient source of tiliroside because the matrix of accompanying components is relatively poor, which facilitates separation.

Simultaneous Determination of 23 Pyrrolizidine and Tropane Alkaloids in Infusions from Dry Edible Flowers Using Optimized μSPEed® Microextraction Prior to Their Analysis by UHPLC-IT-MS/MS

A miniaturized solid-phase extraction of two tropane alkaloids (TAs) and twenty-one pyrrolizidine alkaloids (PAs) from infusions of dry edible flowers using optimized µSPEed® technique was developed. The optimization of the µSPEed® methodology involved testing different cartridges and comparing various volumes and numbers of loading cycles. The final conditions allowed for a rapid extraction, taking only 3.5 min. This was achieved using a C18-ODS cartridge, conditioning with 100 µL of methanol (two cycles), loading 100 µL of the infusion sample (seven cycles), and eluting the analytes with 100 µL of methanol (two cycles). Prior to their analysis by UHPLC-IT-MS/MS, the extracts were evaporated and reconstituted in 100 µL of water (0.2% formic acid)/methanol (0.2% ammonia) 95:5 (v/v), allowing for a preconcentration factor of seven times. The methodology was successfully validated obtaining recoveries ranging between 87 and 97%, RSD of less than 12%, and MQL between 0.09 and 0.2 µg/L. The validated methodology was applied to twenty samples of edible flower infusions to evaluate the safety of these products. Two infusion samples obtained from Acmella oleracea and Viola tricolor were contaminated with 0.16 and 0.2 µg/L of scopolamine (TA), respectively, while the infusion of Citrus aurantium was contaminated with intermedine and lycopsamine (PAs) below the MQL.

Green infant formula analysis: Optimizing headspace solid-phase microextraction of carbonyl compounds associated with lipid peroxidation using GC-MS and pentafluorophenylhydrazine derivatization

The refinement and optimization of a method combining headspace solid-phase microextraction (HS-SPME) with gas chromatography-mass spectrometry (GC-MS) was successfully performed for the first time to determine seven carbonyl and dicarbonyl compounds, including glyoxal, methylglyoxal, dimethylglyoxal, and malondialdehyde in infant formulae, related to lipid peroxidation. HS-SPME was utilized for simultaneous extraction and derivatization with pentafluorophenylhydrazine (PFPH). Critical parameters such as temperature, pH, extractive phase, and salting-out were meticulously investigated and fine-tuned by an asymmetrical 2232//9 screening design to ensure the method's efficacy and reliability. Optimal conditions included a PFPH concentration of 5 g/L, pH 5.0, head-space extraction at 60 °C within 10 min, utilizing a DVB/CAR/PDMS coating, and a 20% w/w salting-out. The analytical validation of this method, compliant with FDA guidelines, demonstrated exceptional linearity, sensitivity, specificity, precision (RSD ≤13.8%), and accuracy (84.8% ≤ recovery ≤111.5%). The metric approach AGREEprep confirms its eco-friendliness, marking a significant step towards an environmentally conscious approach in infant formula analysis. An occurrence study conducted on 25 infant formula samples revealed widespread carbonyl and dicarbonyl compounds in both powdered and liquid variants. ANOVA results exhibited variations in compound concentrations among different sample groups. Clustering analyses delineated distinct groups based on carbonyl content, indicating the potential of these compounds as markers for lipid peroxidation and food quality assessment. This method serves as a valuable tool for evaluating infant formula quality, stability towards oxidation, and safety.

Selective extraction of maleic hydrazide in foods using magnetic molecularly imprinted polymers and colorimetric detection via smartphone

Maleic hydrazide (MH) is a plant growth regulator, herbicide, and sprout inhibitor used to improve the growth and quality of certain vegetables and fruits, unfortunately, MH has genotoxic and carcinogenic effects; thus, MH residues in food need to be analyzed. Herein, magnetic molecularly imprinted polymers (MagMIP) were synthesized by radical polymerization in just 30 min using a microwave for rapid and selective extraction of MH. The colorimetric detection of MH using the immobilized Folin Ciocalteau's reagent (FCR) on 96-well microplate via smartphone sensor exhibits useful sensitivity for MH with a limit of detection (LOD = 0.6 ppm) which is far lower than the maximum residue limits (higher than 5 ppm). The immobilized FCR was stored dry at two different storage conditions at +4 °C and room temperature without losing its performance over six months. The coupling MagMIP-extraction/clean-up and smartphone determination were tested towards food samples (i.e., potatoes, and carrots), obtaining good recovery (79-96 %), high repeatability (RSD 4.5 %; n = 10), and high selectivity for MH determination.

Microplastic pollution: a review of techniques to identify microplastics and their threats to the aquatic ecosystem

Microplastics (MPs), small synthetic particles, have emerged as perilous chemical pollutants in aquatic habitats, causing grave concerns about their disruptive effects on ecosystems. The fauna and flora inhabiting these specific environments consume these MPs, unwittingly introducing them into the intricate web of the food chain. In this comprehensive evaluation, the current methods of identifying MPs are amalgamated and their profound impacts on marine and freshwater ecosystems are discussed. There are many potential risks associated with MPs, including the dangers of ingestion and entanglement, as well as internal injuries and digestive obstructions, both marine and freshwater organisms. In this review, the merits and limitations of diverse identification techniques are discussed, including spanning chemical analysis, thermal identification, and spectroscopic imaging such as Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and fluorescent microscopy. Additionally, it discusses the prevalence of MPs, the factors that affect their release into aquatic ecosystems, as well as their plausible impact on various aquatic ecosystems. Considering these disconcerting findings, it is imperative that appropriate measures should be taken to assess the potential risks of MP pollution, protect aquatic life and human health, and foster sustainable development.

Advanced micro-extraction techniques (SPME, HiSorb) for the determination of goat cheese whey wastewater VOCs

HiSorb and solid-phase microextraction (SPME), two environmentally friendly micro-extraction techniques based on the same fundamental principles, were evaluated for their extraction efficiency of volatile organic compounds (VOCs) from goat cheese whey wastewater. For this purpose, a sample preparation method based on the headspace-HiSorb technique was developed and evaluated for its efficiency in terms of the amount of extracted compounds and reproducibility of results. Thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) and GC/MS analytical methods were used to perform the wastewater analysis, respectively. The experimental parameters of HiSorb were evaluated in terms of probe coating, extraction time, stirring speed, sample volume, extraction temperature and salt addition. Under optimal extraction conditions, it was observed that the use of the divinylbenzene/carbon wide range/polydimethylsiloxane (DVB/CWR/PDMS) triple coating for HiSorb and DVB/Carboxen (CAR)/PDMS for SPME, was best suited to extract a broader range of VOCs with higher peak intensities. A total of 34 VOCs were extracted and determined with the DVB/CWR/PDMS HiSorb probe, while only 23 VOCs were determined with the conventional DVB/CAR/PDMS SPME fiber. The DVB/CWR/PDMS HiSorb probe has a higher adsorbent capacity which results in a higher sensitivity for VOCs compared to the DVB/CAR/PDMS SPME fiber. Furthermore, the HiSorb technique exhibits better reproducibility, as indicated by the lower relative standard deviation (RSD) of 3.7% compared to 7.1% for SPME. Therefore, the HiSorb technique is an effective method for detecting VOCs in complex matrices, such as wastewater.

Design and Optimisation of Sustainable Sample Treatments Based on Ultrasound-Assisted Extraction and Strong Cation-Exchange Purification with Functionalised SBA-15 for Opium Alkaloids in Ground Poppy Seeds

An analysis methodology was optimised and validated for the quantification of opium alkaloids (OAs) in ground poppy seeds. This involved ultrasound-assisted extraction (UAE) and solid-phase extraction (SPE) purification before analysis using a high-performance liquid chromatography mass spectrometry detector (HPLC-MS/MS). UAE was optimised through the design of experiments with three factors and a three-level full factorial design. For SPE optimisation, a commercial material was compared with a previously synthesised material of SBA-15 silica functionalised with sulfonic groups (SBA-15-SO3-). The synthesised material demonstrated superior efficiency with only 25 mg and proved to be reusable for up to four cycles. The methodology was properly validated in terms of linearity, limits of detection and quantification, and selectivity. Matrix effects were negligible; adequate recovery values (85-100%) and inter-day and intra-day precision (≤15%) were obtained. The greenness of the method was evaluated with the AGREEprep metric scale, being more environmentally friendly compared to OA analysis methods. Finally, the method was applied to different samples of ground poppy seeds and revealed a concentration of 140 mg/kg of morphine equivalents in one of the samples, surpassing the legislatively established limits by sevenfold. This highlights the need to analyse these types of samples to mitigate potential public health issues.

Supercritical fluid-based method for selective extraction and analysis of indole alkaloids from Uncaria rhynchophylla

The development of an approach based on simultaneous supercritical fluid extraction-sample cleanup, followed by supercritical fluid chromatography/tandem mass spectrometry (SFE-SFC-MS/MS) was as a tool for the extraction, separation and characterization of indole alkaloids of Uncaria rhynchophylla. A two-step SFE method was designed. A mixture of the U. rhynchophylla sample and an adsorbent named C18SCX with the ratio of 1:1 (w/w) was placed into an extraction cell. The extraction temperature was 40 °C and the pressure was 25 Mpa. In the first step, 10 % EtOH as the co-solvent was used to extract for 60 min, which was considered as a cleanup process to remove non-alkaloid components. In the second step, 0.1 % DEA was added to 10 % EtOH and it extracted for 60 min to obtain the desired extract. By introducing an additional adsorbent, the specificity of SFE towards alkaloids was greatly improved. An SFC-MS/MS method was then utilized for analysis of the SFE extract. Using 2-EP as stationary phase with the gradient elution of 0-10 min, 5-25 % EtOH (+0.05 % DEA) in CO2, column temperature 40 °C, and back pressure 13.8 Mpa, 10 peaks were separated within 8 min. Further MS/MS analysis confirmed that nine of the 10 peaks in the SFE extract were indole alkaloids. This study developed a supercritical fluid-based method specifically towards extraction and analysis of alkaloids, which is helpful to the study of alkaline compounds in complex samples.

Microwave-assisted extraction in closed vessel in food analysis

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.

Optimization and synthesis of a novel sorbent composite based on magnetic chitosan-amine-functionalized bimetallic MOF for the simultaneous dispersive solid-phase microextraction of four aflatoxins in real water, herbal distillate, and food samples

Aflatoxins (AFs), an important category of pollutants, are formed in many foods and adversely affect human health. Therefore, their determination is critical to ensuring human food health. An efficient dispersive solid-phase microextraction technique was developed as a simple and straightforward sample preparation technique for determination of four aflatoxins using a high-performance liquid chromatography (HPLC) fluorescence detector. A novel efficient, green sorbent for extracting AFs was synthesized based on hydrothermal and chemical strategies. The amounts of three sorbent components were optimized using a mixture design (simplex lattice design), including 14 experiments. The optimal amount of amino-bimetallic Fe/Ni-MIL-53 nanospheres, chitosan, and magnetic Fe3O4 nanoparticles as sorbent components was 0.87, 0.67, and 0.47 g, respectively. Also, various factors affecting the process of AF determination were studied and optimized in two successive experimental designs, including the definitive screening design and the Box-Behnken design. Under optimal conditions, the linear ranges for measuring aflatoxin B1, aflatoxin B2, aflatoxin G1, and aflatoxin G2 were 0.05-82.6, 0.07-86.4, 0.08-85.7, and 0.07-89.5 ng mL-1, respectively. The relative standard deviations under inter-day and intra-day conditions for measuring AFs at three analyte concentrations were determined in triplicate analysis and were in the ranges of 3.7-4.6% and 4.9-6.1% for water sample analysis, respectively. The qualitative detection limits for determining AFs were between 0.01 and 0.05 ng mL-1. The pre-concentration factor of the method for measuring AFs ranged from 739.7 to 802.1. The proposed method was used for determining AFs in several real samples, including herbal distillate, black tea, corn, and real water samples. The relative recovery and standard deviation were 87.8-97.8% and 4.10-6.82%, respectively.

Optimization of QuEChERS Extraction for Determination of Carotenoids, Polyphenols, and Sterols in Orange Juice Using Design of Experiments and Response Surface Methodology

Several compounds with different physical properties are present in foods, biological components, and environmental samples, and there are cases in which these must be analyzed simultaneously. However, it is difficult to extract compounds with different physical properties from the same sample using a single method. In the present study, we examined the optimal conditions for the QuEChERS extraction of several kinds of compounds from orange juice using design of experiments (DoE) and response surface methodology (RSM) to determine the optimal ratio of organic solvent to sodium chloride. We determined the optimal extraction conditions, which were within the design space, using 100% tetrahydrofuran (THF) as the extraction organic solvent and NaCl:MgSO4 = 75:25 as the salt. The developed LC/MS/MS method using QuEChERS extraction achieved specific detection and precise quantification. Finally, we measured the polyphenols, sterols, and carotenoids in citrus juice using the optimized QuEChERS extraction method before LC/MS/MS analysis. Most of the analytes were quantifiable in orange juice. The optimized method achieved ease of operation, the extraction of analytes from food samples in a short time (within 30 min), minimization of analytical residues, and reliability. The DoE and RSM approach may contribute to better optimization of the extraction conditions for the lowest number of experiments.

Recent advances in the combination of organic solvent-free extraction, chemical standardization, antioxidant assay, and cell culture metabolomics for functional food and its by-product

Functional foods and their by-products contain a wide range of bioactive components with an array of health benefits and were proposed to improve public health, well-being, and others. To achieve a circular economy, the processing and extraction of flavonoids, phenolic compounds, and others from functional food and agri-food wastes will require the use of environmentally friendly, sustainable, and a low-cost solution. Extraction methods that can eliminate the use of organic solvents, suitable for use in the laboratory and production of extracts will be covered. This will include subcritical water extraction (SBE), pressurized hot water extraction (PHWE), supercritical fluid extraction (SFE), and others. Based on the selected analytical methods, the determination of the marker or bioactive compounds and chemical fingerprints will provide the control measures to identify the batch-to-batch variation of the composition of the functional food products obtained. The combination of chemical standardization with antioxidant assay, such as DPPH and ABTS+ will provide further information on the quality of the extracts. Lastly, to ascertain the biological and physiological relevance of the antioxidant properties of the target sample, treatment of the antioxidant compounds or extracts was carried out using cellular models, and validated using other experimental endpoints, such as metabolomics.

Simultaneous microextraction of pesticides from wastewater using optimized μSPEed and μQuEChERS techniques for food contamination analysis

Food contamination with pesticides poses significant risks to consumer safety and undermines confidence in food supply chains. Detecting pesticides in food samples is a challenging task that requires efficient extraction techniques. This study aims to compare and validate two microextraction techniques, μSPEed and μQuEChERS-dSPE, for the simultaneous extraction of eight pesticides (paraquat, thiabendazole, asulam, picloram, ametryn, atrazine, linuron, and cymoxanil) from wastewater samples. A good analytical performance was obtained for both methodologies, with selectivity, linearity in the range 0.5-150 mg L^-1 with coefficients of determination up to 0.9979, limits of detection (LODs) and limits of quantification (LOQs) ranging from 0.02 to 0.05 mg L^-1 and from 0.06 to 0.17 mg L^-1, respectively, precision below 14.7 mg L^-1, and recoveries from wastewater samples in the range of 66.1-99.9%. The developed methodologies are simpler, faster, and require less sample and solvent volumes than conventional methodologies, having a lower impact on the environment. Nevertheless, the μSPEed approach was found to be more efficient, easier to perform, and with a higher greener profile. This study highlights the potential of microextraction techniques for the analysis of pesticide residues in food and environmental samples. Overall, it presents a fast and efficient method for the analysis of pesticides in wastewater samples, which can be useful for monitoring and controlling pesticide contamination in the environment.

Differences in the Volatilomic Urinary Biosignature of Prostate Cancer Patients as a Feasibility Study for the Detection of Potential Biomarkers

Prostate cancer (PCa) continues to be the second most common malignant tumour and the main cause of oncological death in men. Investigating endogenous volatile organic metabolites (VOMs) produced by various metabolic pathways is emerging as a novel, effective, and non-invasive source of information to establish the volatilomic biosignature of PCa. In this study, headspace solid-phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME/GC-MS) was used to establish the urine volatilomic profile of PCa and identify VOMs that can discriminate between the two investigated groups. This non-invasive approach was applied to oncological patients (PCa group, n = 26) and cancer-free individuals (control group, n = 30), retrieving a total of 147 VOMs from various chemical families. This included terpenes, norisoprenoid, sesquiterpenes, phenolic, sulphur and furanic compounds, ketones, alcohols, esters, aldehydes, carboxylic acid, benzene and naphthalene derivatives, hydrocarbons, and heterocyclic hydrocarbons. The data matrix was subjected to multivariate analysis, namely partial least-squares discriminant analysis (PLS-DA). Accordingly, this analysis showed that the group under study presented different volatomic profiles and suggested potential PCa biomarkers. Nevertheless, a larger cohort of samples is required to boost the predictability and accuracy of the statistical models developed.

Optimization of Carob Products Preparation for Targeted LC-MS/MS Metabolomics Analysis

Carob (Ceratonia siliqua) is an exceptional source of significant bioactive compounds with great economic importance in the Mediterranean region, where it is widely cultivated. Carob fruit is used for the production of a variety of products and commodities such as powder, syrup, coffee, flour, cakes, and beverages. There is growing evidence of the beneficial effects of carob and the products made from it on a range of health problems. Therefore, metabolomics could be used to explore the nutrient-rich compounds of carob. Sample preparation is a crucial step in metabolomics-based analysis and has a great impact on the quality of the data obtained. Herein, sample preparation of carob syrup and powder was optimized, to enable highly efficient metabolomics-based HILIC-MS/MS analysis. Pooled powder and syrup samples were extracted under different conditions by adjusting pH, solvent type, and sample weight to solvent volume ratio (Wc/Vs). The metabolomics profiles obtained were evaluated using the established criteria of total area and number of maxima. It was observed that the Wc/Vs ratio of 1:2 resulted in the highest number of metabolites, regardless of solvent type or pH. Aqueous acetonitrile with a Wc/Vs ratio of 1:2 satisfied all established criteria for both carob syrup and powder samples. However, when the pH was adjusted, basic aqueous propanol 1:2 Wc/Vs and acidic aqueous acetonitrile 1:2 Wc/Vs provided the best results for syrup and powder, respectively. We strongly believe that the current study could support the standardization of the metabolomics sample preparation process to enable more efficient LC-MS/MS carob analysis.

Approaches to determine pesticides in marine bivalves

Due to agricultural runoff, pesticides end up in aquatic ecosystems and some accumulate in marine bivalves. As filter feeders, bivalves can accumulate high concentrations of chemicals in their tissue representing a potential risk to the health of human and aquatic ecosystems. So far, most of the studies dealing with pesticide contamination in marine bivalves, for example, in the French Atlantic and English Channel coasts, have focused on the old generation of pesticides. Only a few investigated the newly emerging pesticides partly due to methodological challenges. A better understanding of the most sensitive and reliable methods is thus essential for accurately determining a wide variety of environmentally relevant pesticides in marine bivalves. The review highlighted the use of more environmentally friendly and efficient materials such as sorbents and the "quick easy cheap effective rugged safe" extraction procedure to extract pesticides from bivalve matrices, as they appeared to be the most efficient while being the safest. Moreover, this method combined with the high-resolution mass spectrometry (MS) technique offers promising perspectives by highlighting a wide range of pesticides including those that are not usually sought. Finally, recent developments in the field of ultra-high-performance liquid chromatography coupled to MS, such as two-dimensional chromatography and ion mobility spectrometry, will improve the analysis of pesticides in complex matrices.

Synthesis and Characterization of a Multi-Walled Carbon Nanotube-Ionic Liquid/Polyaniline Adsorbent for a Solvent-Free In-Needle Microextraction Method

Sample preparation is an essential process when handling complex matrices. Extraction without using a solvent requires the direct transfer of analytes from the sample to the adsorbent either in the gas or liquid phase. In this study, a wire coated with a new adsorbent was fabricated for in-needle microextraction (INME) as a solvent-free sample extraction method. The wire inserted into the needle was placed in the headspace (HS), which was saturated with volatile organic compounds from the sample in a vial. A new adsorbent was synthesized via electrochemical polymerization by mixing aniline with multi-walled carbon nanotubes (MWCNTs) in the presence of an ionic liquid (IL). The newly synthesized adsorbent using IL is expected to achieve high thermal stability, good solvation properties, and high extraction efficiency. The characteristics of the electrochemically synthesized surfaces coated with MWCNT-IL/polyaniline (PANI) adsorbents were characterized using Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). Then, the proposed HS-INME-MWCNT-IL/PANI method was optimized and validated. Accuracy and precision were evaluated by analyzing replicates of a real sample containing phthalates, showing spike recovery between 61.13% and 108.21% and relative standard deviations lower than 15%. The limit of detection and limit of quantification of the proposed method were computed using the IUPAC definition as 15.84~50.56 μg and 52.79~168.5 μg, respectively. We concluded that HS-INME using a wire coated with the MWCNT-IL/PANI adsorbent could be repeatedly used up to 150 times without degrading its extraction performance in an aqueous solution; it constitutes an eco-friendly and cost-effective extraction method.

New insights of the application of water or ethanol-water plant extract rich in active compounds in food

Plants are recognized as natural sources of antioxidants (e.g., polyphenols, flavonoids, vitamins, and other active compounds) that can be extracted by green solvents like water, ethanol, or their binary mixtures. Plant extracts are becoming more used as food additives in various food systems due to their antioxidant abilities. Their application in food increases the shelf life of products by preventing undesirable changes in nutritional and sensory properties, such as the formation off-flavors in lipid-rich food. This review summarizes the most recent literature about water or ethanol-water plant extracts used as flavors, colorings, and preservatives to fortify food and beverages. This study is performed with particular attention to describing the benefits of plant extract-fortified products such as meat, vegetable oils, biscuits, pastries, some beverages, yogurt, cheese, and other dairy products. Antioxidant-rich plant extracts can positively affect food safety by partially or fully replacing synthetic antioxidants, which have lately been linked to safety and health issues such as toxicological and carcinogenic consequences. On the other hand, the limitations and challenges of using the extract in food should be considered, like stability, level of purity, compatibility with matrix, price, sensory aspects like distinct taste, and others. In the future, continuous development and a tendency to use these natural extracts as food ingredients are expected, as indicated by the number of published works in this area, particularly in the past decade.

Polyaniline and Polyaniline-Based Materials as Sorbents in Solid-Phase Extraction Techniques

Polyaniline (PANI) is one of the best known and widely studied conducting polymers with multiple applications and unique physicochemical properties. Due to its porous structure and relatively high surface area as well as the affinity toward many analytes related to the ability to establish different types of interactions, PANI has a great potential as a sorbent in sample pretreatment before instrumental analyses. This study provides an overview of the applications of polyaniline and polyaniline composites as sorbents in sample preparation techniques based on solid-phase extraction, including conventional solid-phase extraction (SPE) and its modifications, solid-phase microextraction (SPME), dispersive solid-phase extraction (dSPE), magnetic solid-phase extraction (MSPE) and stir-bar sorptive extraction (SBSE). The utility of PANI-based sorbents in chromatography was also summarized. It has been shown that polyaniline is willingly combined with other components and PANI-based materials may be formed in a variety of shapes. Polyaniline alone and PANI-based composites were successfully applied for sample preparation before determination of various analytes, both metal ions and organic compounds, in different matrices such as environmental samples, food, human plasma, urine, and blood.

Alternative Ecosorbent for the Determination of Trihalomethanes in Aqueous Samples in SPME Mode

A new sorbent material based on modified clay with ionic liquid immobilized into an agarose film was developed as part of this study. It was applied to determine organochlorine pollutants, like disinfection byproducts, through headspace solid-phase microextraction-gas chromatography-electron capture detection (HS-SPME-GC-ECD). The disinfection byproducts determined in this study were used as model molecules because they were volatile compounds, with proven severe effects on human health. Their presence in aquatic environments is in trace concentrations (from pg L^-1 to mg L^-1). They are classified as emergent pollutants and their determination is a challenge for analytical chemists. The parameters which affected the extraction efficiency, i.e., number and distance between SPME discs, salt concentration, the temperature of extraction, extraction time, and desorption time, were optimized. A wide linear dynamic range of 10-1000 ng mL^-1 and coefficients of determination better than 0.997 were achieved. The limits of detection and the limits of quantitation were found in the ranges of (1.7-3.7) ng mL^-1 and (5.6-9.9) ng mL^-1, respectively. The precision, expressed as relative standard deviation (RSD), was better than 8%. The developed sorbent exhibits good adsorption affinity. The applicability of the proposed methodology for the analysis of trihalomethanes in environmental and water samples showed recoveries in the range of 86-95%. Finally, the newly created method fully complied with the principles of green chemistry. Due to the fact that the sorbent holder was made of agarose, which is a wholly biodegradable material, sorbent clay is a widespread material in nature. Moreover, the reagents intercalated into the montmorillonite are new green solvents, and during the whole procedure, low amounts of organic solvents were used.

Recent advances in the analysis of polycyclic aromatic hydrocarbons in food and water

Polycyclic aromatic hydrocarbons (PAHs), a class of harmful and persistent organic contaminant, are widely distributed in the environment and eventually accumulated in water and food. Also, they are formed in different varieties and varying amounts during processing of food depending on the food composition, cooking method and processing condition. According to the International Agency for Research on Cancer (IARC), various PAHs are classified under Group 1 to 3 category, with Group 1 designated as carcinogenic to humans, Group 2A as probable carcinogen, Group 2B as possible carcinogen and Group 3 as noncarcinogenic. Therefore, it is imperative to develop rapid and highly sensitive analytical methods for determination of PAHs in food and water. This article aims to overview the recent advances of various chromatographic methods as well as electrochemical and SERS-based optical sensing methods for analysis of PAHs in food and water. Initially, several conventional sample preparation methods along with the advanced extraction for isolation of PAHs were summarized, followed by reviewing various gas chromatographic methods coupled with various detection techniques for PAHs analysis in various food products including meat/meat products, seafood, oil, milk/milk products, baby foods, honey, vegetable, cocoa products, tea/coffee, juice, rice, flour, noodle and cake. In addition, high performance liquid chromatographic methods coupled with fluorescence, diode array or mass/tandem mass detection techniques as well as an emerging supercritical fluid chromatographic technique employed for determination of PAHs in different food and water matrices were also overviewed. Finally, various electrochemical sensors and SERS-based optical sensors developed recently for onsite detection of PAHs were tabulated and discussed. Thus, this review article can provide a research update on chromatography and sensor-based analytical methods for PAH analysis as well as enable elucidation of research gaps for future studies.

Impact of Sample Pretreatment and Extraction Methods on the Bioactive Compounds of Sugar Beet (Beta vulgaris L.) Leaves

To find the most optimal green valorization process of food by-products, sugar beet (Beta vulgaris L.) leaves (SBLs) were freeze-dried and ground with/without liquid nitrogen (LN), as a simple sample pretreatment method, before ultrasound-assisted extraction (UAE) of polyphenols. First, the water activity, proximate composition, amino acid (AA) and fatty acid (FA) profiles, and polyphenol oxidase (PPO) activity of dried and fresh SBLs were evaluated. Then, conventional extraction (CE) and UAE of polyphenols from SBLs using water/EtOH:water 14:6 (v/v) as extracting solvents were performed to determine the individual and combined effects of the sample preparation method and UAE. In all the freeze-dried samples, the specific activity of PPO decreased significantly (p ≤ 0.05). Freeze-drying significantly increased (p ≤ 0.05) the fiber and essential FA contents of SBLs. The FA profile of SBLs revealed that they are rich sources of oleic, linoleic, and α-linolenic acids. Although freeze-drying changed the contents of most AAs insignificantly, lysine increased significantly from 7.06 ± 0.46% to 8.32 ± 0.38%. The aqueous UAE of the freeze-dried samples without LN pretreatment yielded the most optimal total phenolic content (TPC) (69.44 ± 0.15 mg gallic acid equivalent/g dry matter (mg GAE/g DM)) and excellent antioxidant activities. Thus, combining freeze-drying with the aqueous UAE method could be proposed as a sustainable strategy for extracting bioactive compounds from food by-products.

Volatilomics as an Emerging Strategy to Determine Potential Biomarkers of Female Infertility: A Pilot Study

Due to its high prevalence, infertility has become a prominent public health issue, posing a significant challenge to modern reproductive medicine. Some clinical conditions that lead to female infertility include polycystic ovary syndrome (PCOS), endometriosis, and premature ovarian failure (POF). Follicular fluid (FF) is the biological matrix that has the most contact with the oocyte and can, therefore, be used as a predictor of its quality. Volatilomics has emerged as a non-invasive, straightforward, affordable, and simple method for characterizing various diseases and determining the effectiveness of their current therapies. In order to find potential biomarkers of infertility, this study set out to determine the volatomic pattern of the follicular fluid from patients with PCOS, endometriosis, and POF. The chromatographic data integration was performed through solid-phase microextraction (SPME), followed by gas chromatography–mass spectrometry (GC-MS). The findings pointed to specific metabolite patterns as potential biomarkers for the studied diseases. These open the door for further research into the relevant metabolomic pathways to enhance infertility knowledge and diagnostic tools. An extended investigation may, however, produce a new mechanistic understanding of the pathophysiology of the diseases.

Green Synthesis of Molecularly Imprinted Polymers for Dispersive Magnetic Solid-Phase Extraction of Erythrosine B Associated with Smartphone Detection in Food Samples

Monitoring synthetic colorants in foods is important due to their potential toxicity and pathogenicity. We propose here a new and simple method for the extraction and determination of erythrosine B (ERT-B) in food samples. A composite of polydopamine-based molecularly imprinted polymers coating magnetic nanoparticles (Fe₃O₄@PDA@MIP) was synthesized using a green approach and exploited for the magnetic dispersive solid-phase extraction (MDSPE) of ERT-B. Fe₃O₄@PDA@MIP provides a rapid extraction of ERT-B, exhibiting good reusability and preconcentration ability. Moreover, the MIP showed a relatively good imprinting factor (3.0 ± 0.05), demonstrating excellent selectivity against patent blue (an interfering dye) and other food matrix components. The proposed MDSPE was coupled to colorimetric smartphone-based detection that allowed us to obtain similar performances of UV-Vis spectroscopy detection. The smartphone-based optical detection facilitated the determination of ERT-B in the 0.5-10 mg/L range, with a limit of detection of 0.04 mg/L. The developed method was successfully employed to determine ERT-B in food samples (juice, candy, and candied cherries) with good recovery values (82-97%).

Improved Analytical Approach for Determination of Tropane Alkaloids in Leafy Vegetables Based on µ-QuEChERS Combined with HPLC-MS/MS

This work presents an optimized methodology based on the miniaturization of the original QuEChERS (μ-QuEChERS) followed by liquid chromatography coupled to mass spectrometry (HPLC-MS/MS) for the determination of tropane alkaloids (TAs), atropine, and scopolamine in leafy vegetable samples. The analytical methodology was successfully validated, demonstrating quantitation limits (MQL) ≤ 2.3 ng/g, good accuracy, and precision, with recoveries between 90–100% and RSD ≤ 13% for both analytes. The method was applied to the analysis of TA-producing plants (Brugmansia versicolor, Solandra maxima, and Convolvulus arvensis). High concentrations of scopolamine were found in flowers (1771 mg/kg) and leaves (297 mg/kg) of B. versicolor. The highest concentration of atropine was found in flowers of S. maxima (10.4 mg/kg). Commercial mixed leafy vegetables contaminated with B. versicolor and S. maxima were analysed to verify the efficacy of the method, showing recoveries between 82 and 110% for both analytes. Finally, the method was applied to the analysis of eighteen samples of leafy vegetables, finding atropine in three samples of mixed leafy vegetables, with concentrations of 2.7, 3.2, and 3.4 ng/g, and in nine samples with concentrations ≤MQL. In turn, scopolamine was only found in a sample of chopped Swiss chard with a concentration ≤MQL.

Volatilomics: An Emerging and Promising Avenue for the Detection of Potential Prostate Cancer Biomarkers

Simple Summary

The lack of highly specific and sensitive biomarkers for the early detection of prostate cancer (PCa) is a major barrier to its management. Volatilomics emerged as a non-invasive, simple, inexpensive, and easy-to-use approach for cancer screening, characterization of disease progression, and follow-up of the treatment’s success. We provide a brief overview of the potential of volatile organic metabolites (VOMs) for the establishment of PCa biomarkers from non-invasive matrices. Endogenous VOMs have been investigated as potential biomarkers since changes in these VOMs can be characteristic of specific disease processes. Recent studies have shown that the conjugation of the prostate-specific antigen (PSA) screening with other methodologies, such as risk calculators, biomarkers, and imaging tests, can attenuate overdiagnosis and under-detection issues. This means that the combination of volatilomics with other methodologies could be extremely valuable for the differentiation of clinical phenotypes in a group of patients, providing more personalized treatments.

Abstract

Despite the spectacular advances in molecular medicine, including genomics, proteomics, transcriptomics, lipidomics, and personalized medicine, supported by the discovery of the human genome, prostate cancer (PCa) remains the most frequent malignant tumor and a leading cause of oncological death in men. New methods for prognostic, diagnostic, and therapy evaluation are mainly based on the combination of imaging techniques with other methodologies, such as gene or protein profiling, aimed at improving PCa management and surveillance. However, the lack of highly specific and sensitive biomarkers for its early detection is a major hurdle to this goal. Apart from classical biomarkers, the study of endogenous volatile organic metabolites (VOMs) biosynthesized by different metabolic pathways and found in several biofluids is emerging as an innovative, efficient, accessible, and non-invasive approach to establish the volatilomic biosignature of PCa patients, unravelling potential biomarkers. This review provides a brief overview of the challenges of PCa screening methods and emergent biomarkers. We also focus on the potential of volatilomics for the establishment of PCa biomarkers from non-invasive matrices.

Overview of Different Modes and Applications of Liquid Phase-Based Microextraction Techniques

Liquid phase-based microextraction techniques (LPµETs) have attracted great attention from the scientific community since their invention and implementation mainly due to their high efficiency, low solvent and sample amount, enhanced selectivity and precision, and good reproducibility for a wide range of analytes. This review explores the different possibilities and applications of LPμETs including dispersive liquid–liquid microextraction (DLLME) and single-drop microextraction (SDME), highlighting its two main approaches, direct immersion-SDME and headspace-SDME, hollow-fiber liquid-phase microextraction (HF-LPME) in its two- and three-phase device modes using the donor–acceptor interactions, and electro membrane extraction (EME). Currently, these LPμETs are used in very different areas of interest, from the environment to food and beverages, pharmaceutical, clinical, and forensic analysis. Several important potential applications of each technique will be reported, highlighting its advantages and drawbacks. Moreover, the use of alternative and efficient “green” extraction solvents including nanostructured supramolecular solvents (SUPRASs, deep eutectic solvents (DES), and ionic liquids (ILs)) will be discussed.

Valorization of Spent Sugarcane Fermentation Broth as a Source of Phenolic Compounds

A methodology based on a solid phase extraction (SPE) was optimized for the recovery of phenolic compounds from the spent fermentation broth generated from Biofene® (trans-β-farnesene) production. For this purpose, two resins (XAD-2 and HP-20) and three desorption solutions (water, 50/50 ethanol/water, and ethanol) were tested. The most efficient resin revealed to be the HP-20, using ethanol as desorption solution, reaching an overall total phenolic compound recovery of ca. 80% when 6 BV (bed volume) of both feed and ethanol were applied. The optimization of the resin’s process cycle pointed to 15 BV feed to be treated per cycle and using the same volume of ethanol in the desorption step, with no need for an extra resin regeneration step, stably yielding 48% total phenolic compound recovery from the spent broth for at least 4 cycles, translating into 60 BV of feed being treated per BV of resin, and with the resin being still perfectly active. The extract was characterized using LC−ESI−UHR−QqTOF−MS, and a total of 82 and 15 compounds were identified, in negative and positive ionization modes, respectively. Organic acids were the main class of compounds identified in the phenolic-rich extract, followed by phenolic compounds, saccharides, peptides or amino acids and vitamins. Additionally, the extract revealed a significant antioxidant capacity (914.1 ± 51.6 and 2764.5 ± 142.8 µmol Trolox equivalents/g-dw, respectively, with ABTS and ORAC methodologies), which might be interesting for a wide variety of applications.

Salt-Induced Homogeneous Liquid–Liquid Microextraction of Piroxicam and Meloxicam from Human Urine Prior to Their Determination by HPLC-DAD

A salt-induced homogeneous liquid–liquid microextraction (SI-HLLME) protocol combined with high-performance liquid chromatography–diode array detection is presented for the first time for the determination of piroxicam and meloxicam in human urine. The main parameters affecting the performance of the sample preparation protocol were optimized by means of a two-step experimental design (i.e., 2-level fractional factorial design and Box–Behnken design). Following its optimization, the proposed method was thoroughly validated in terms of the total error concept in order to take into consideration the random and systematic errors. For the target analytes, accuracy profiles were constructed, and they were used as graphical decision-making tools. In all cases, the β-expectation tolerance intervals complied with the acceptance criteria of ±15%, proving that 95% of future results will fall within the defined bias limits. The limits of detection were 0.02 μg mL−1 and 0.03 μg mL−1 for piroxicam and meloxicam, respectively. The relative standard deviations were lower than 4.4% in all cases, and the mean relative biases ranged between −5.7 and 3.4% for both drugs. The proposed scheme is simple and rapid, while it is characterized by high sample throughput. Moreover, SI-HLLME requires reduced sample and reagent consumption, according to the requirements of Green Analytical Chemistry.