Sulfur has a significant impact on environmental geochemistry, mineral formation, magmatic evolution and biogeochemical cycling, among other geological processes. Accurate identification and quantification of sulfur species in geological materials remain analytically challenging due to their complex mineral matrix, variable oxidation states, and susceptibility to change during sample preparation. This review offers a thorough evaluation of current developments in the investigation of sulfur species in a variety of geological materials, such as rocks, ores, sediments, and fluid inclusions. The strengths, limitations, and analytical performance of several established and emerging techniques, including X-ray Absorption Spectroscopy (XANES/EXAFS), Electron Probe Microanalysis (EPMA), Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS), Ion Chromatography-High-Performance Liquid Chromatography (IC-HPLC), combustion-based methods, Raman spectroscopy, and synchrotron-based microanalytical tools were assessed. The preservation of oxidation states, detection limits, matrix effects, and method standardization are all given special consideration. To improve accuracy and resolution in sulfur speciation, current trends such as multi-method integration, microscale and nanoscale analytical advancements, and machine learning-assisted data interpretation are explored. Lastly, we highlight important knowledge gaps and suggest future lines of inquiry for improving analytical robustness, creating reference materials, and building high-resolution, non-destructive characterisation procedures. The importance of analytical innovation in advancing our understanding of sulfur behaviour in geological systems and enabling broader applications in geochemical modelling, environmental monitoring, and mineral exploration is highlighted in this review.
The reliable determination of trace metals in environmental, food, industrial, and biological matrices depends on effective sample-preparation strategies that enable analyte preconcentration, minimize matrix-induced interferences, and preserve species stability prior to atomic spectrometric measurement. Solid-phase extraction (SPE) remains a widely adopted approach due to its operational versatility, low solvent consumption, and compatibility with offline, online, dispersive, and magnetic formats. Within this context, silica nanoparticles have emerged as a highly adaptable class of sorbents, not merely because of their high surface area, but due to the chemical precision with which their solid-liquid interface can be engineered to regulate selectivity, binding strength, and compatibility with diverse extraction configurations. This review provides a critical, application-oriented assessment of silica nanoparticle-based SPE systems, tracing their structural evolution from dense Stöber-derived particles to mesoporous silica nanoparticles (MSNs), magnetic core-shell architectures, hollow and bimodal structures, dendritic fibrous (e.g., KCC-1) materials, and hybrid composites. Unlike conventional classifications based primarily on material type, this work organizes the discussion around the analytical limitations that each structural design was intended to address, including diffusion constraints, limited accessibility of active sites, sorbent recovery challenges, and matrix-related suppression effects. Several persistent sources of terminological ambiguity are systematically clarified. In particular, Stöber-derived silica is shown to be chemically equivalent to base or acid catalysed sol-gel silica rather than a distinct class. Likewise, micron-scale ordered mesoporous silicas such as MCM-41 and SBA-15 are distinguished from their mesoporous nanoscale counterparts, which are commonly referred to as MSNs. The progression from dense to hierarchical and hybrid architectures is therefore interpreted as a sequence of design responses to analytical constraints rather than a simple optimization of surface area. The review further highlights developments in the synthesis of SNPs from sustainable silicate precursors and emphasizes the need for standardized reporting practices to ensure methodological reproducibility and cross-study comparability. The key remaining challenges, particularly nanoparticle aggregation, batch-to-batch variability, ligand leaching, and inconsistent analytical validation, are critically evaluated. Finally, key research priorities are outlined, focusing on greener synthesis routes, improved structural control, and harmonized performance metrics for rigorous evaluation. Hence, this work provides a consolidated framework for the rational design and application of SNPs-based SPE sorbents in the analysis of trace metals in complex matrices.
Conventional lipid extraction workflows (e.g., Folch or Bligh-Dyer) remain difficult to integrate into high-throughput automation because they rely on centrifugation, manual phase handling, and labor-intensive solvent-transfer steps. This study introduces a streamlined one-pot thermomorphic workflow that addresses these bottlenecks by exploiting the temperature-programmed phase behavior of a cyclohexane/methanol system with a literature upper critical solution temperature (UCST) of 45.5°C at x(MeOH) = 0.506. Heating above the UCST enables simultaneous thermal extraction and acid-catalyzed transesterification in a homogeneous single phase. Passive cooling then regenerates the biphasic state, partitioning fatty acid methyl esters (FAMEs) into a directly injectable cyclohexane-rich upper phase for gas chromatography–tandem mass spectrometry (GC–MS/MS) without centrifugation, solvent transfer, or evaporative concentration.The selected operating point (65°C, 20 min, φ = 0.50, defined before acetyl chloride addition) was obtained from multivariate screening with an inter-replicate relative standard deviation (RSD) of 2.45%. Calibration yielded linear responses for ten target FAMEs (R² ≥ 0.9672), with limits of detection of 0.070–2.3 mg L⁻¹ and limits of quantification of 0.24–7.8 mg L⁻¹. BCR-162R provided analyte-specific spike-recovery data for five C16–C18 FAMEs, with strongest agreement for C18:2n6-ME and defined limitations for C18:0-ME, C18:1n9-ME, and C18:3n3-ME. Application to six commercial food matrices demonstrated operational feasibility but also matrix- and target-panel-dependent quantitative limitations. NIST SRM 3275 defined the applicability boundary for long-chain polyunsaturated fatty acids (LC-PUFAs) in marine oil. AGREEprep benchmarking gave scores of 0.46 (default) and 0.64 (context-adjusted), indicating a resource-efficient, automation-compatible alternative to conventional lipid sample-preparation workflows.
Solvent-assisted matrix precipitation, followed by centrifugation, supernatant subtraction, solvent evaporation, and reconstitution, is a commonly used yet laborious procedure for preparing complex sample matrices. Its automation has not yet been tested using flow approaches, despite the potential to save time and consumables and yield higher procedural reproducibility. To tackle this challenging issue, we have developed a Lab-In-Syringe-automated methodology coupled online to HPLC for the determination of water-soluble vitamins B1, B2, B3, B6, B9, and B12 in plant-based milk alternatives.Salt-assisted homogeneous liquid-liquid extraction, automated using an automatic syringe pump, was used to simultaneously denature proteins and separate the precipitable sample matrix from oat, soy, hazelnut, almond, and coconut milk substitutes. The organic phase was passed into a secondary, coupled automatic syringe pump that used preheated air for solvent evaporation.To the best of our knowledge, this is the first report on combining fully automated matrix precipitation and solvent evaporation in flow techniques. This way, we achieved a significant improvement in analyte concentration compared to earlier reported in-syringe deproteination, where significant extract dilution had been required to achieve compatibility with HPLC.Highlighted features include a sub-milliliter sample volume, a total processing time of only 9 min, including intermediate system cleaning, and online coupled HPLC-UV analysis of the extract in parallel with sample processing, yielding a sample throughput of 5/h. Adequate analytical performance for routine analysis was achieved with quantitative protein elimination, LOQs of 0.5–2.7 µg/L, and RSDs of 1.1–2.6 %, < 5% omitting an internal standard. Analysis of milk samples, both genuine and spiked, yielded an average recovery of 92 ± 11 %.
Pre-analytical variations, particularly apoptotic stress responses in blood samples, remain a critical challenge in transcriptomic data harmonization. A major source of this noise is the interference caused by anticoagulants, specifically heparin, which inhibits downstream enzymatic reactions and induces ex vivo stress artifacts that confound gene expression profiles Unlike traditional immediate lysis methods, our approach introduces lithium chloride (LiCl) prior to sample storage to exert a protective effect that mitigates stress-induced cellular damage and reduces apoptosis. Furthermore, LiCl is applied again prior to the RNA precipitation step to serve as a decontamination agent. This LiCl-based protocol is particularly effective for rescuing archived blood samples contaminated with heparin and stored under long-term frozen conditions (-80 °C for up to 180 days). Key results demonstrate that LiCl treatment significantly restores RNA integrity (P < 0.01), achieving an average RIN value > 7.0. Notably, we observed that adding LiCl during the storage of hypoxia-stressed whole blood samples significantly reduced cell apoptosis (P < 0.001). Consequently, little inter-sample variability was observed, and the transcriptomic profiles of rescued samples show high concordance with those from EDTA-anticoagulated controls, enabling high-quality sequencing without the need for complex computational normalization. Thus, this LiCl-based method offers a robust, cost-effective, and environmentally friendly alternative for high-fidelity blood transcriptomics, especially valuable for precious clinical cohorts where re-sampling is not feasible. However, due to LiCl's selective precipitation of larger RNA fragments (>200 nt), this protocol is not suitable for analyses targeting small RNAs such as microRNAs.
Due to their significant surface area and tunable surface chemistry, polymer nanofibers are promising advanced sorbents for miniaturized solid phase extraction of a broad range of model analytes that differ in chemical structures and physical properties. In this study, in-situ modified and coated polyamide 6 nanofibers were evaluated as sorbents for spin-filter solid phase extraction. The modified nanofibers were produced by electrospinning from polymer solutions containing either 3-[dodecyl(dimethyl)ammonio]-1-propanesulfonate (sulfobetaine 12) or tetramethylammonium chloride. Alternatively, the nanofibers were coated with sulfonated azo dyes. This surface modification of nanofibers was identified as a key factor in governing sorbent performance, and led to significantly enhanced extraction efficiency compared to native and uncoated materials. Among the tested sorbents, tartrazine-coated nanofibers exhibited the highest extraction efficiency, particularly for phenolic acids and non-steroidal anti-inflammatory drugs. Recoveries exceeded 90% for most analytes. The developed spin-filter solid phase extraction method coupled with ultra-high performance liquid chromatography with spectrophotometric detection showed good accuracy (85.8–106.6%) and precision (RSD ≤ 4.7%). Applying the method to analyze river water confirmed the suitability of the sorbent for extracting polar xenobiotics prior to chromatographic analysis.
An automated, miniaturized QuEChERS-type sample-preparation workflow was developed for the determination of twelve priority phthalates in edible oils by gas chromatography–tandem mass spectrometry (GC–MS/MS): dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-propyl phthalate (DNPP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), di-n-hexyl phthalate (DNHP), benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP). The workflow integrates temperature-controlled double extraction (2 × 3 mL acetonitrile at 80 °C) to improve robustness for high-melting matrices, PSA/C18 dispersive clean-up, and in-vial performic acid epoxidation to mitigate olefinic interferences (e.g., squalene), followed by GC–MS/MS (MRM) with column backflush. Epoxidation was implemented in the final isooctane extract without an additional post-epoxidation concentration step, enabling simultaneous quantification across the complete target analyte set, including lower-molecular-weight phthalates. Performance evaluation in squalene-rich amaranth oil showed linear calibration (R² > 0.99) and good precision (RSD ≤ 10% at 0.1 and 1 mg/kg; DINP and DIDP at 1 and 10 mg/kg). LOQs were 2.7–41 µg/kg for DMP–DNOP, while DINP and DIDP showed higher LOQs (93 and 272 µg/kg). Two edible-oil proficiency-test samples agreed with assigned values within acceptable performance limits. AGREEprep benchmarking improved from 0.12 (ISO reference workflow) to 0.23, mainly driven by miniaturization and automation. Future work will address higher LOQs for DINP and DIDP, optimize clean-up for medium-chain triglycerides (MCT)-rich matrices, and expand validation to a broader range of edible oils.
The bacterial volatilome is rich in information that can be exploited for metabolic investigations and infectious disease diagnostics, including identification and, potentially, rapid antimicrobial susceptibility testing. Robust and reliable headspace sampling is critical for the capture of bacterial emissions. Here, we introduce a standardized bacterial headspace sampling technique for reproducible and real-time analysis of bacterial growth plates. The system is based on an inert volume sampler for the accumulation and triggered extraction of trace-level microbial volatile organic compounds (mVOCs) from inoculated samples under controlled temperature and relative humidity (e.g., 37 °C and 80%, respectively). Integrated sample dilution is achieved using high-resolution mass flow controllers to meet the dynamic range requirements of various analytical tools, for instance, mass spectrometers and chemical sensors. A built-in analyte gas standard enables calibration between measurements. The sampling characteristics are assessed for key mVOCs (acetaldehyde, acetone, benzene, and ethanol) within relevant concentration ranges, down to 50 parts-per-billion by volume (ppb) levels. In vitro tests with DSM 613 Escherichia coli confirm accurate capture of mVOC dynamics reflecting physiological changes during bacterial growth, as monitored by proton transfer reaction time-of-flight mass spectrometry over 24 h. This setup offers a standardized approach compatible with diverse analytical tools for exploring the microbial volatilome.
An automated, miniaturized QuEChERS-type sample-preparation workflow was developed for the determination of twelve priority phthalates in edible oils by gas chromatography-tandem mass spectrometry (GC-MS/MS): dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-propyl phthalate (DNPP), diisobutyl phthalate (DIBP), dibutyl phthalate (DBP), di-n-hexyl phthalate (DNHP), benzyl butyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di(2-ethylhexyl) phthalate (DEHP), di-n-octyl phthalate (DNOP), diisononyl phthalate (DINP), and diisodecyl phthalate (DIDP). The workflow integrates temperature-controlled double extraction (2 & times; 3 mL acetonitrile at 80 degrees C) to improve robustness for high-melting matrices, PSA/C18 dispersive clean-up, and in-vial performic acid epoxidation to mitigate olefinic interferences (e.g., squalene), followed by GC-MS/MS (MRM) with column backflush. Epoxidation was implemented in the final isooctane extract without an additional post-epoxidation concentration step, enabling simultaneous quantification across the complete target analyte set, including lower-molecular-weight phthalates. Performance evaluation in squalene-rich amaranth oil showed linear calibration (R & sup2; > 0.99) and good precision (RSD <= 10% at 0.1 and 1 mg/kg; DINP and DIDP at 1 and 10 mg/kg). LOQs were 2.7-41 & micro;g/kg for DMP-DNOP, while DINP and DIDP showed higher LOQs (93 and 272 & micro;g/kg). Two edible-oil proficiency-test samples agreed with assigned values within acceptable performance limits. AGREEprep benchmarking improved from 0.12 (ISO reference workflow) to 0.23, mainly driven by miniaturization and automation. Future work will address higher LOQs for DINP and DIDP, optimize clean-up for medium-chain triglycerides (MCT)-rich matrices, and expand validation to a broader range of edible oils.
A rapid, sustainable, and efficient analytical method based on Rotating Disk Sorptive–Dispersive Extraction (RDSDE) coupled to HPLC–DAD was developed and validated for the determination of florfenicol in animal plasma. The method employs a magnetic activated carbon (MAC) sorbent derived from avocado seed, an agricultural waste material, combining high extraction efficiency with improved environmental performance. Key extraction parameters were optimized, achieving optimal conditions with 20 mg of MAC, an extraction time of 20 min, and acetone as desorption solvent with a desorption time of 5 min.The method was fully validated in porcine plasma, demonstrating excellent selectivity, linearity (R² ≥ 0.9967), precision (RSD ≤ 7.2%), and accuracy (recovery ≥ 91%) over the concentration range of 0.5–10 mg L⁻¹. Dilution integrity was confirmed up to 20 mg L⁻¹, and robustness was demonstrated with respect to sorbent batch variability. Applicability to bovine plasma was also verified, confirming the method’s robustness toward matrix variation.A kinetic comparison between RDSDE and conventional Rotating Disk Sorptive Extraction (RDSE) revealed markedly faster extraction kinetics for RDSDE, reaching equilibrium within 20 min, whereas RDSE required substantially longer extraction times under comparable conditions. In addition to its analytical performance, the method was evaluated using AGREE, AGREEprep, BAGI, and RAPI metrics, confirming its classification as a white analytical method that balances metrological robustness, environmental sustainability, and operational practicality.Overall, the proposed RDSDE followed by HPLC-DAD methodology represents a technically innovative and environmentally responsible alternative for florfenicol determination in animal plasma, offering significant advantages for veterinary pharmacokinetic studies and residue monitoring.
For the first time, polymer microfibers filled in pipette tip format were used to extract polycyclic aromatic hydrocarbons from river water. Centrifugal force was used to push the sample through the sorbent, thereby increasing the speed and throughput of the extraction process. A broad range of almost 30 different microfibrous materials, including various polymers and their coated counterparts, were evaluated to identify the most efficient sorbent. Biodegradable polycaprolactone microfibers provided the best recovery rates (72–127%) with relative standard deviations (RSD) of 2.7–6.4%. The method exhibited linearity from 0.1 to 5 µg L⁻¹ for most analytes (R² > 0.9994), except for dibenzo(a,h)anthracene (R² = 0.9981). Preconcentration factors ranged from 2.9 to 5.1. Intra- and inter-day repeatability tests confirmed stability and reusability of the sorbent for over six consecutive extraction cycles conducted within three experimental days. The high permeability of polycaprolactone microfibers allows for short contact times while maintaining high recoveries. The centrifuge-assisted setup enables the processing of up to 36 samples per run. Our approach provides a practical alternative for extracting hydrophobic analytes from water. The novelty of this study lies in the development of a reusable, centrifugation-driven pipette-tip microextraction approach using biodegradable polycaprolactone microfibers for fast and efficient determination of polycyclic aromatic hydrocarbons in water.
Antibiotics are by design difficult to remove in the biological treatment of wastewater and are becoming ubiquitous in aquatic environments, which bears the risk for the formation of resistant bacterial strains. The new EU Urban Wastewater Treatment Directive demands fast, cheap, efficient, and environmentally-friendly methods for antibiotic determination. However, there is a general need for sample preparation and analyte preconcentration. For this purpose, liquid phase extractions remain reliable and often-used approaches, while they show drawbacks regarding procedural greenness. Herein, we applied dispersive liquid-liquid microextraction based on a hydrophobic natural deep eutectic solvent for the first time for the fully automated enrichment of the selected antibiotics tetracycline, oxytetracycline, doxycycline, chlortetracycline, sulfamethoxazole, and trimethoprim from surface waters. The methodology was based on the Lab-In-Syringe technique and was coupled online to high-performance liquid chromatography with spectrophotometric detection. Sample and solvent handling and extraction were carried out inside the void of a computer-controlled syringe with a multiposition head valve with an integrated magnetic stir bar for efficient solvent dispersion. The procedure required 200 & micro;L solvent and was completed within 8 min, including all cleaning steps, and was operated in parallel to the chromatographic analysis of the previous extract. A greenness evaluation by the AGREE tool yielded a value of 0.8. Excellent linearity up to 1000 & micro;g L- 1, detection limits ranging from 0.4 to 15 mu g L-1, and RSD values typically below 4.3% were achieved. The method was successfully applied to the determination of selected antibiotics in surface waters, demonstrating its practical application.
The aim of this research was to develop a new extraction method combining hydrophobic deep eutectic solvent (HDES)-based microemulsion systems with microwave-assisted extraction (MAE) technology to enhance the extraction efficiency of isoangustone A (IsoA) from the leaves of the Thai medicinal plant Derris scandens (Roxb.) Benth. (Fabaceae). The research optimized the extraction parameters, characterized the microemulsion formulations, and evaluated the anti-inflammatory potential of the preparations in vitro. The HDES (menthol:lactic acid, 1:2 mol ratio)-microemulsion formulation demonstrated enhanced extraction efficiency over conventional ethanol-based methods. This formulation achieved a yield of IsoA of 6.52 μg/mg, surpassing the 5.76 μg/mg yield obtained through ethanol extraction. Response Surface Methodology (RSM) modeling enabled precise optimization of the extraction parameters, reaching 91.2 % predictive accuracy. Physicochemical characterization revealed that HDES-based microemulsions maintained 23.1–50.7 nm size, facilitating an enhanced bioavailability profile. The incorporation of D. scandens leaf extracts into the HDES (menthol:lactic acid, 2:1 mol ratio)-based microemulsion provided optimal inhibition of LPS-induced NO production in RAW264.7 macrophages, with IC50 values (9.07±2.26 μg/mL) substantially lower than the DMSO-solubilized counterparts (53.7±3.8 μg/mL) demonstrating enhanced cell penetration resulting in improved extraction. This integrated approach represents a significant advancement in sustainable extraction technology, offering enhanced recovery of bioactive compounds while preserving their biological properties for further assessment.
A semi-automated micro solid-phase extraction (μSPE) method has been developed and optimized for the quantification of 21 per- and polyfluoroalkyl substances (PFAS) across various biological matrices, including plasma, serum, urine, and liver tissue. This method employed μSPE cartridges integrated with a PAL-RTC robotic system, which enabled precise flow control and high-throughput procedures while ensuring exceptional extraction efficiency and reproducibility. Sample homogenization of liver tissues was achieved by bead-mill technology which eliminated sample cross-contamination and significantly reduced processing time. The extraction efficiency was influenced by the concentration of methanol in the sample, especially for longer-chain PFAS (C9–14). Extraction efficiencies of over 90% extraction were achieved with loading solutions containing 50–60% methanol in plasma and serum, and up to 80% methanol in water samples. The μSPE protocol included two sequential wash steps that provided excellent matrix clean-up, and reduced background signals by over 95% compared to traditional protein precipitation (PP) methods. The µSPE-LC-MS/MS method offers high sensitivity (method detection limits between 0.008 ng/mL and 0.048 ng/mL), along with good recoveries (90.3 to 105.1%), and precision (RSD <10%). It also demonstrated strong agreement with non-certified values of NIST Standard Reference Materials (SRM 1957/1958). The method was successfully used in the analysis of PFAS in human urine and plasma, as well as in mouse liver samples from an in vivo study. The μSPE approach provides a sensitive, reproducible, and automated solution that requires limited biological sample volumes, making it suitable for the analysis of PFAS in biomonitoring and toxicokinetic studies.
The use of hydrophobic and aromatic polymer nanofibers as novel sorbents for extracting polycyclic aromatic hydrocarbons (PAHs) from river water has been evaluated. Of the materials tested, the biodegradable aliphatic polymer polycaprolactone (PCL) exhibited strong retention of all analytes via hydrophobic interactions. In contrast, the aromatic polymer polyphenylene sulfide (PPS) demonstrated superior performance with higher-ring PAHs due to a combination of hydrophobic and π–π stacking interactions. The porous, permeable structure of the fibrous sorbents enabled rapid extraction. The spin-filter µSPE format required only 10 s for sorbent activation, extraction, and elution, resulting in a total processing time of 30 s per sample. Up to 48 samples could be processed simultaneously, reducing manual handling and simplifying the workflow. Analytical performance was evaluated using river water spiked at different concentration levels. The method showed good linearity (R² ≥ 0.98) across concentration ranges of 0.1–5 µg L⁻¹ for most analytes, with limits of detection of 0.009–0.14 µg L⁻¹ for PCL and 0.012–0.27 µg L⁻¹ for PPS. Recoveries ranged from 57 to 102 % for PCL and 88–139 % for PPS, with relative standard deviations below 15 %, and preconcentration factors of approximately twofold. These results demonstrate that meltblown PCL and PPS nanofibers combined with spin-filter µSPE provide a rapid and practical approach to extracting PAHs from environmental water samples.
Tetracyclines are widely used antibiotics in animal farming, raising concerns over their residues in food and associated health risks. Current methods for residue determination are complex, time-consuming, and produce substantial solvent waste. Electromembrane extraction (EME) offers high clean-up efficiency, minimal solvent use, and direct LC-MS/MS compatibility. This study evaluates EME for extraction of four tetracyclines (oxytetracycline, tetracycline, chlorotetracycline, doxycycline) from complex matrices including milk, egg white, honey, and human plasma. Optimal parameters varied across matrices, underscoring the need for matrix-specific optimization. Optimized methods achieved recoveries of 66–101 %, excellent linearity (R² = 0.9929–0.9998), and minimal matrix effects (-14 % to 1 %). LLOQs ranged from 0.5 to 2.1 ng/g, with calibration curves extending to 1000 ng/g, covering concentrations relevant for residue monitoring. These results demonstrate EME’s potential for reliable analysis of challenging polar and zwitterionic compounds in food and biological samples. Finally, the greenness was evaluated by the AGREEprep metric tool, gaining a total score of 0.64.
A miniaturized and environmentally conscious analytical workflow was developed and validated for the extraction, purification, and quantification of major glycoalkaloids (alpha-solanine, alpha-chaconine), the degradation product gamma-chaconine, and the aglycone solanidine in potato-based snack products. The method combines ultrasound-assisted extraction (UAE) with pipette-tip solid-phase extraction (PT-SPE), followed by UHPLC-MS/ MS analysis. UAE conditions were optimized using a Box-Behnken statistical design, which evaluated the extraction time, ultrasound amplitude, and solid:liquid (SL) ratio. Optimal conditions were determined to be 5 min, 100 % amplitude, and a 1:9 w/v of SL ratio, with methanol as the most effective extraction solvent. MSU-2-C18 mesostructured silica sorbent, packed into pipette tips (5 mg) connected to a SPE vacuum manifold (VMA-PT-SPE), was employed under the optimized conditions to simultaneously purify up to 12 extracts. The method's greenness was evaluated using the AGREEprep metric, yielding a score of 0.65, indicating good environmental performance. Limits of detection (LOD) and quantification (LOQ), ranging from 0.55-4.40 mu g/kg and 1.82-14.67 mu g/kg, respectively, were achieved for the target analytes. Application to four commercial potato-based snacks revealed major (alpha-solanine and alpha-chaconine) and minor glycoalkaloids (gamma-chaconine and solanidine) levels, ranging from 2.0 to 16.0 mg/kg fresh weight, highlighting substantial variability among products and providing a more comprehensive characterization of the glycoalkaloid profile. Compared to conventional SPE formats, this UAE-VMA-PT-SPE strategy offers superior reproducibility while reducing sample and solvent consumption. The method represents a powerful tool for routine monitoring of glycoalkaloids in potato snacks, supporting food safety assessments and addressing analytical priorities established by the European Food Safety Authority.
Proteinaceous materials are useful precursors for preparing sustainable and cost-effective sorptive phases. Among them, chicken egg white is an excellent alternative, serving as a source of ovalbumin that can be used as a biosorbent. In this article, the combination of egg white with cellulose paper is evaluated to synthesize a planar protein-based sorptive phase with high porosity and surface area. For this purpose, the paper was dip-coated in egg-white, followed by thermal curing that induced protein denaturation and self-crosslinking. The preparation was quite simple and affordable, since it did not require subsequent functionalization procedures, allowing the preparation of 25 sorptive phases with only 1 mL of pasteurized egg white. The resulting egg-white paper (EW-paper) enabled the isolation of the analytes through a mixed-mode interaction mechanism, comprising both hydrophobic and cation-exchange interactions. This potential was corroborated by evaluating the extraction capacity of the EW-paper towards some selective serotonin reuptake inhibitors (SSRI) (fluoxetine, paroxetine, sertraline, and venlafaxine) from saliva samples. The analytes were finally determined by direct infusion mass spectrometry analysis. Once optimized, the method allows the determination of the target compounds in the low µgL-1 range, also fulfilling the validation criteria in terms of precision (better than 9.1 % and 11.8 % in intra- and inter-day precision, respectively) and accuracy (in the range 84 -118 %). Finally, the applicability of the method was demonstrated by analyzing real saliva samples from a patient under paroxetine treatment.
In this study, a novel and environmentally friendly analytical procedure was developed for the fast separation and preconcentration of ultra-trace levels of lead from water samples at room temperature. The method is based on a hydrophobic deep eutectic solvent–assisted rapid synergistic cloud point extraction (HDES-RS-CPE), followed by electrothermal atomic absorption spectrometry (ETAAS) for quantification. The selected HDES was composed of L-menthol and 1-octanol in a 1:1 molar ratio, while ammonium pyrrolidine dithiocarbamate (APDC) and Triton X-114 were employed as the chelating agent and nonionic surfactant, respectively. Key experimental parameters influencing extraction efficiency were systematically investigated and optimized. Under optimal conditions, the method achieved a limit of detection (LOD) of 0.04 µg/L, a limit of quantification (LOQ) of 0.12 µg/L, and an enrichment factor (EF) of 38, with spike recoveries ranging from 94% to 104%. The method’s greenness, practicality and robustness were confirmed using various metrics demonstrated compliance with the principles of Green Analytical Chemistry, highlighting the method’s potential as a sustainable and efficient approach for ultra-trace lead quantification in environmental samples.
