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In this study, a comprehensive and sensitive method for the simultaneous detection of 17 opioids (OPs) and their human metabolites in wastewater using high-performance liquid chromatography coupled to tandem mass spectrometry was validated. The chromatographic separations of opioids were carried out on a Kinetex® Biphenyl column (1.7 μm, 100 Å, 50 × 2.1 mm). A synthetic wastewater approach was used for recovery studies to mimic a contaminant-free matrix. Two solid-phase extraction (SPE) sorbents (hydrophilic-lipophilic balance and mixed mode with the previous phase and a weak cationic exchange) were studied to optimize sample treatment and obtain higher recoveries. The mixed mode was chosen because the recoveries of 17 target analytes at three spiked concentrations (25, 50, and 100 ng mL -1 ) were > 80 % for 75 % of the analytes in a simulated wastewater. The intra- and inter-day relative standard deviations (RSDs) were between ±1 % and ±20 %. The method limits of quantification ranged from 5 to 25 ng L -1 , the only exceptions being heroin (275 ng L -1 ) and morphine-3β-glucuronide (250 ng L -1 ). Suppression/enhancement is comparable between the synthetic and the influent wastewater. The analytical method was applied to the OPs analysis in twenty-one influent samples collected from the treatment plants treating the wastewater of Valencia City (Spain). Twelve OPs were detected with total daily concentrations ranging from 1 ng L -1 to 2135 ng L -1 . The widespread presence of these compounds in water suggests potential widespread exposure, highlighting the need for increased environmental awareness. Furthermore, the estimated daily intake results raise concerns about opioid use as a potential future health and social issue., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The demand for plant-based protein sources in the food industry has significantly increased in recent years, leading to the introduction of legume-based products as meat substitutes. However, concerns regarding food quality have emerged, particularly related to the presence of mycotoxins. This study addresses the need for the sensitive detection of phomopsins (PHOs), a class of peptide-based toxins. A selective extraction method using molecularly imprinted polymer (MIP) coupled with ultra-high performance liquid chromatography and tandem mass spectrometry (UHPLC-MS/MS) was focused on the most toxic Phomopsin A (PHO-A). A rapid ultrasonochemical synthesis of MIP (5 min) was proposed and its performance was optimized in response to various factors, including the choice of dummy template and the selection of the monomer. The methacrylic acid-vinyl pyridine (MAA-VP) MIP exhibited high selectivity and affinity for PHO-A. The method was tested in lupin samples and the validation, according to SANTE/11312/2021 international guidelines, gave excellent recovery (80-90 %), low matrix effects, and high accuracy and precision. Real samples analysis confirmed the presence of PHO-A in artificially fungal inoculated lupins, with levels ranging from 0.377 to 0.576 mg kg -1 . In order to identify further PHOs, a semi-untargeted approach using multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) was developed. PHO-B, PHO-D, PHO-E and PHO-P, rarely previously reported in lupin matrix, were tentatively identified. This study accounts for the effectiveness of MIP-based extraction coupled with UHPLC-triple quadrupole with linear ionic trap-MS/MS (UHPLC-QqQ-LIT-MS/MS) for quantification of PHO-A and putative detection of other PHOs, offering a promising method for investigating this class of toxins in food., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

N,N'-Substituted p-phenylenediamine quinones (PPD-Qs) are the emerging toxicant, which transform from the rubber tire antioxidant N,N'-substituted p-phenylenediamines (PPDs). Because of their potential toxic and widespread occurrence in the environment, PPD-Qs have received great attention. However, efficiently extracting PPD-Qs from complex samples is still a challenge. Herein, a cysteine functional covalent organic framework (Cys-COF) designed according to the "donor-acceptor" sites of hydrogen bonding of PPD-Qs was synthesized via click reaction and then used as solid-phase extraction (SPE) adsorbent. Cys-COF can form the seven-member ring adsorption structure with PPD-Qs via hydrogen bonding. The adsorption mechanism was tentatively revealed by density functional theory (DFT). After optimizing the Cys-COF-SPE parameters, PPD-Qs were efficiently extracted from water, soil, sediment, and fish, followed by detection using ultra-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). The Cys-COF-SPE-UHPLC-MS/MS method exhibited ideal linearity (R 2 ≥ 0.9932), high relative recoveries (80.4-111 %), and low limits of detection (0.0001-0.0013 ng mL -1 ). In addition, the bioconcentration kinetics in goldfish provides a feasible platform to investigate the toxicity and accumulated ability of PPD-Qs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Alkyl imidazolium ionic liquids (Cn[MIM]), initially heralded as eco-friendly green solvents for diverse industrial applications, have increasingly been recognized fortheir biodegradability challenges and multiple biotoxicity. Despite potential health risks, research into the effects of Cn[MIM] on human health remains scarce, particularly regarding their detection in biological serum samples. This study validated a matrix-matched calibration quantitative method that utilizes solid-phase extraction (SPE) coupled with ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The method was used to analyze the presence of 10 ionic liquids (ILs) with varying alkyl carbon chain lengths (C 2 -C 12 ) across 300 human serum samples. Efficient separation was achieved using optimized SPE conditions and a BEH C18 column with an appropriate mobile phase. Results demonstrated a strong linear relationship (0.05-100 ng/mL; R 2  = 0.995-0.999), with detection and quantification limits with detection and quantification limits ranging from 0.001 to 0.107 ng/mL and 0.003-0.355 ng/mL, respectively. Intraday and inter-day precisions were 0.85-6.99 % and 1.50-7.46 %, with recoveries between 82 and 113 %. The validated method detected C 6 MIM in 19 % of samples and C 8 MIM in 8.3 % of samples, with concentrations ranging from 0.02 to 111.70 μg/L and 0.09-16.99 μg/L, respectively, suggesting a potential risk of human exposure. This underscores the importance of robust detection methods in monitoring environmental and human health impacts of alkyl imidazolium compounds., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The aim of this study was to develop a high-performance liquid chromatography-tandem mass spectrometry method for the determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma samples. Strata-X 33 μm solid-phase extraction cartridges were used for the extraction of the catecholamines from human plasma samples. The catecholamines were separated in a 150 × 3 mm Shim-pack GIST C 18 -AQ column with 3 μm particle size, placed in an oven at 40°C and perfused with 82% mobile phase A (acetonitrile-H 2 O; 90:10, v/v) + 0.4% acetic acid and 18% mobile phase B (deionized H 2 O) + 0.2% formic acid at a flow rate of 340 μl/min in isocratic mode. The injected volume was 4 μl and the run lasted 4 min. The method was linear from 0.1 to 20 ng/ml and the lower limit of quantification was 0.1 ng/ml for all analytes. The method was applied to evaluate the plasma levels of catecholamines in plasma of patients with chronic kidney disease and allowed the detection for the first time of circulating levels of the novel catecholamines 6-bromodopamine and 6-cyanodopamine., (© 2024 John Wiley & Sons Ltd.)

Phosphoenolpyruvate (PEP) is an essential intermediate metabolite that is involved in various vital biochemical reactions. However, achieving the direct and accurate quantification of PEP in plasma or serum poses a significant challenge owing to its strong polarity and metal affinity. In this study, a sensitive method for the direct determination of PEP in plasma and serum based on ethylenediaminetetraacetic acid (EDTA)-facilitated hydrophilic interaction liquid chromatography-tandem mass spectrometry was developed. Superior chromatographic retention and peak shapes were achieved using a zwitterionic stationary-phase HILIC column with a metal-inert inner surface. Efficient dechelation of PEP-metal complexes in serum/plasma samples was achieved through the introduction of EDTA, resulting in a significant enhancement of the PEP signal. A PEP isotopically labelled standard was employed as a surrogate analyte for the determination of endogenous PEP, and validation assessments proved the sensitivity, selectivity, and reproducibility of this method. The method was applied to the comparative quantification of PEP in plasma and serum samples from mice and rats, as well as in HepG2 cells, HEK293T cells, and erythrocytes; the results confirmed its applicability in PEP-related biomedical research. The developed method can quantify PEP in diverse biological matrices, providing a feasible opportunity to investigate the role of PEP in relevant biomedical research., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A magnetic biochar nanomaterial derived from fungal hyphae was introduced into the sample preparation field. The magnetic fungal hyphae-derived biomass carbon (MFHBC) could be produced by a controllable hydrothermal method. In order to obtain the best sorbent for magnetic solid-phase extraction (MSPE), the reaction conditions containing temperature, time and the consumption of fungal hyphae were investigated. A series of MFHBC materials were characterized by vibrating sample magnetometers, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and transmission electron microscopy. A material with a satisfactory saturation magnetization (21.58 emu g-1) and largest surface area (88.06 m2 g-1) was selected as the sorbent to extract ten typical organochlorine pesticides (OCPs). The extraction conditions were optimized as 20 mL of sample solution with 70 mg of sorbent and 2.0 g of NaCl oscillated at 50 °C for 5.0 min. And the optimum desorption was performed by oscillating sorbent in 1.0 mL acetonitrile for 5.0 min. Then, the MFHBC-based MSPE-GC-MS/MS methods were established for different samples including water samples, tea beverages, and Chinese traditional medicines. The linearities were 10-2500 ng L -1 or 100-25,000 ng kg -1 , and the limits of detection were 0.3-13.9 ng L -1 for water sample, 0.1-9.7 ng L -1 for tea beverage samples, 0.1-21.4 ng L -1 for Shenqi Fuzheng injection samples, and 7.2-278.3 ng kg -1 for Astragali Radix decoction pieces. Except for satisfactory repeatability (RSDs ≤13.8%) in intra-day and inter-day tests (n = 3), the reproducibility (RSDs ≤13.5%, n = 3) of MFHBC was acceptable. The methods were applied in the determination of OCPs from above real samples, with the recoveries of 80.5-117.2% and the RSDs (n = 3) <8.9%. The methods were suitable in the sensitive determination of OCPs from simple to complex matrix samples., Competing Interests: Declaration of competing interest None., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

This study presents a method based on acid transesterification and the purification by solid-phase extraction (SPE) coupled with gas chromatography-tandem mass spectrometry for quantifying 3- and 2-monochloropropanediol esters (3-MCPDE, 2-MCPDE) and glycidyl esters (GE) in nutritional foods. The fat was extracted by liquid-liquid extraction with petroleum ether and diethyl ether after the sample was hydrolysed with ammonia. Then the extract was purified by a SPE cartridge filled with the aminopropyl sorbents. It was demonstrated that the optimal elution volume for 3-MCPDE, 2-MCPDE and GE greatly depended on the sample matrix and varied from 6 to 12 mL for four different kinds of food matrices. All three analytes in the sample solution could be fully collected in the first 10-12 mL of eluate. By this way, monoacylglycerols commonly present in the samples were fully removed. Therefore, the overestimation of GE quantification was effectively eliminated. The modified analytical procedure was fully validated in a single laboratory and has been recommended as a Chinese Food Safety National Standard. In addition, two derivatisation agents, heptafluorobutyrylimidazole and phenylboronic acid, were proved to be equivalent in method accuracy and precision for the quantification of three analytes.

N-Acyl-homoserine lactones (AHL) play a major role in the communication of Gram-negative bacteria. They influence processes such as biofilm formation, swarming motility, and bioluminescence in the aquatic environment. A comprehensive analytical method was developed to elucidate the "chemical communication" in pure bacterial cultures as well as in the aquatic environment and engineered environments with biofilms. Due to the high diversity of AHLs and their low concentrations in water, a sensitive and selective LC-ESI-MS/MS method combined with solid-phase extraction was developed for 34 AHLs, optimized and validated to quantify AHLs in bacterial conditioned medium, river water, and treated wastewater. Furthermore, the developed method was optimized in terms of enrichment volume, internal standards, limits of detection, and limits of quantification in several matrices. An unanticipated variety of AHLs was detected in the culture media of Pseudomonas aeruginosa (in total 8 AHLs), Phaeobacter gallaeciensis (in total 6 AHLs), and Methylobacterium mesophilicum (in total 15 AHLs), which to our knowledge have not been described for these bacterial cultures so far. Furthermore, AHLs were detected in river water (in total 5 AHLs) and treated wastewater (in total 3 AHLs). Several detected AHLs were quantified (in total 24) using a standard addition method up to 7.3±1.0 µg/L 3-Oxo-C 12 -AHL (culture media of P. aeruginosa)., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

Per- and polyfluoroalkyl substances (PFASs) and polychlorinated naphthalenes (PCNs) are of growing concern due to their toxic effects on the environment and human health. There is an urgent need for strategies to monitor and analyze the coexistence of PFASs and PCNs, especially in food samples at trace levels, to ensure food safety. Herein, a novel β-cyclodextrin (β-CD) derived fluoro-functionalized covalent triazine-based frameworks named CD-F-CTF was firstly synthesized. This innovative framework effectively combines the porous nature of the covalent organic framework and the host-guest recognition property of β-CD enabling the simultaneous extraction of PFASs and PCNs. Under the optimal conditions, a simple and rapid method was developed to analyze PFASs and PCNs by solid-phase extraction (SPE) based simultaneous extraction and stepwise elution (SESE) strategy for the first time. When coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), this method achieved impressive detection limits for PFASs (0.020 -0.023 ng/g) and PCNs (0.016 -0.075 ng/g). Furthermore, the excellent performance was validated in food samples with recoveries of 76.7-107 % (for PFASs) and 78.0-108 % (for PCNs). This work not only provides a simple and rapid technique for simultaneous monitoring of PFASs and PCNs in food and environmental samples, but also introduces a new idea for the designing novel adsorbents with multiple recognition sites., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Urinary eicosanoid concentrations reflect inflammatory processes in multiple diseases and have been used as biomarkers of disease as well as suggested for patient stratification in precision medicine. However, implementation of urinary eicosanoid profiling in large-scale analyses is restricted due to sample preparation limits. Here we demonstrate a single solid-phase extraction of 300 µL urine in 96-well-format for prostaglandins, thromboxanes, isoprostanes, cysteinyl-leukotriene E 4 and the linoleic acid-derived dihydroxy-octadecenoic acids (9,10- and 12,13-DiHOME). A simultaneous screening protocol was also developed for cortisol/cortisone and 7 exogenous steroids as well as 3 cyclooxygenase inhibitors. Satisfactory performance for quantification of eicosanoids with an appropriate internal standard was demonstrated for intra-plate analyses (CV = 8.5-15.1%) as well as for inter-plate (n = 35) from multiple studies (CV = 22.1-34.9%). Storage stability was evaluated at - 20 °C, and polar tetranors evidenced a 50% decrease after 5 months, while the remaining eicosanoids evidenced no significant degradation. All eicosanoids were stable over 3.5-years in urine stored at - 80 °C. This method will facilitate the implementation of urinary eicosanoid quantification in large-scale screening., Competing Interests: Declaration of Competing Interest JK receives consulting fees from Gesynta Pharma AB., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Quantitative information on blood metabolites can be used in developing advanced medical strategies such as early detection and prevention of disease. Monitoring bioactive lipids such as steroids, bile acids, and PUFA metabolites could be a valuable indicator of health status. However, a method for simultaneously measuring these bioactive lipids has not yet been developed. Here, we report a LC/MS/MS method that can simultaneously measure 144 bioactive lipids, including steroids, bile acids, and PUFA metabolites, from human plasma, and a sample preparation method for these targets. Protein removal by methanol precipitation and purification of bioactive lipids by solid-phase extraction improved the recovery of the targeted compounds in human plasma samples, demonstrating the importance of sample preparation methods for a wide range of bioactive lipid analyses. Using the developed method, we studied the plasma from healthy human volunteers and confirmed the presence of bioactive lipid molecules associated with sex differences and circadian rhythms. The developed method of bioactive lipid analysis can be applied to health monitoring and disease biomarker discovery in precision medicine., Competing Interests: Conflict of interest The author declares that they have no conflicts of interest with the contents of this article., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The use of growth hormone-releasing hormones (GHRHs) is prohibited in sports according to the regulations of the World Anti-Doping Agency (WADA). Considering the complexity of urine samples and the low concentrations at which these analytes should be detected, analyzing GHRHs is a challenging task. In most of the studies, GHRHs are analyzed using UHPLC-HRMS with an orbitrap. The present developed and validated method for some GHRHs (tesamorelin, CJC-1295, sermorelin (GRF 1-29), sermorelin (3-29)-NH 2 , somatorelin) is based on the triple quadrupole UHPLC/MS-MS method with solid phase extraction (SPE) with weak cation exchange and is able to detect concentrations as low as 0.2 ng/mL (LOD), a limit of quantification (LOQ) at 0.6 ng/mL, and linearity across the range of 0.1 ng/mL to 1.2 ng/mL. The present method developed by our doping control laboratory was validated according to WADA technical documents for selectivity, limit of detection (LOD), carryover, reliability of detection, stability and recovery. The results show that the method has adequate recoveries and sensitivity, hence, it can be employed for routine screening in anti-doping laboratories., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Inc. All rights reserved.)

A new analytical technique involving protein precipitation, heating, lipid degreasing, and SPE procedures combined with HPLC-UV and HPLC-MS/MS has been developed for the determination of neotame in a variety of food samples. This method is applicable for high-protein, high-lipid, or gum-based solid samples. The limit of detection of the HPLC-UV method was 0.5 μg/mL, while that of the HPLC-MS/MS method was 3.3 ng/mL. The spiked recoveries of neotame in 73 kinds of foods were in the range of 81.1-107.2 % with UV detection. The spiked recoveries obtained by HPLC-MS/MS in 14 kinds of foods ranged from 81.6 % to 105.8 %. This technique was successfully used to determine the contents of neotame in two positive samples, indicating its applicability in food analysis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

In this work, a novel triazine-based porous organic polymers, TAPT-BPDD, was firstly synthesized by a facile method at room temperature. After characterized by FT-IR, FE-SEM, XRPD, TGA, and nitrogen-sorption experiments, TAPT-BPDD was applied as solid-phase extraction (SPE) adsorbent for the extraction of four trace nitrofuran metabolites (NFMs) from meat samples. The key parameters including the adsorbent dosage, sample pH, type and volume of eluents, type of washing solvents were evaluated in the extraction process. Combined with ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF-MS/MS) analysis, good linear relationship (1-50 µg·kg -1 , R 2 >0.9925) and low limits of detection (LODs, 0.05-0.56 µg·kg -1 ) were obtained under the optimal conditions. When spiked at different level, the recoveries were in the range of 72.7-111.6%. The adsorption isothermal model and extraction selectivity of TAPT-BPDD were also studied in detail. The results showed that TAPT-BPDD was a kind of promising SPE adsorbent for the enrichment of organics in food samples., Competing Interests: Declaration of Competing Interest The authors declare no competing interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The metabolome and lipidome are critical components in illustrating biological processes and pathological mechanisms. Generally, two or more independent methods are required to analyze the two compound panels due to their distinct chemical properties and polarity differences. Here, a novel strategy integrating stepwise solid-phase extraction (SPE) and dansyl chemical derivatization was proposed for all-in-one injection LC-MS/MS analysis of serum metabolome and lipidome. In this workflow, a stepwise elution procedure was firstly optimized to separate the metabolome and lipidome fractions using an Ostro plate. Dansyl chemical derivatization was then applied to label amine/phenol, carboxyl, and carbonyl-containing sub-metabolomes. Our results demonstrated that the dansyl labeling could significantly improve chromatographic separation, enhance the MS response, and overcome the matrix effect of co-eluting lipids. Ultimately, an all-in-one injection LC-MS/MS method measuring 256 lipids (covering 20 subclasses) and 212 metabolites (including amino acids, bile acids, fatty acids, acylcarnitines, indole derivatives, ketones and aldehydes, nucleic acid metabolism, polyamines, etc.) was established. This method was applied to investigate the metabolic changes in cisplatin-induced nephrotoxicity in rats and the results were compared with previous untargeted metabolomics. The presented strategy could predominantly improve the analytical coverage and throughput and can be of great use in discovering reliable potential biomarkers in various applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

N-acyl homoserine lactones (N-HLs) are signaling molecules synthesized by gram-negative bacteria to communicate in a process called quorum sensing. Most reported methods for the analysis of N-HLs, which are chiral molecules, do not distinguish between enantiomers. Typical examples include biosensors, liquid chromatography with UV detection, gas chromatography coupled with a mass spectrometer (GC-MS) and liquid chromatography coupled with mass spectrometer (LC-MS). Recently, the production of both D,L-N-HLs have been reported in Vibrio fischeri and Burkholderia cepacia. Concentrations of the D-N-HLs were found at the limit of quantification for the employed method. Therefore, for further studies of the role of the D-N-HLs in bacterial physiology, more sensitive, reliable, and selective analytical methods are necessary. In this work, such comprehensive chiral analytical methods for the identification and determination of 18 N-HLs using solid phase extraction followed by GC-MS/MS and LC-MS/MS analyses were developed. Extraction recoveries for the more hydrophilic C4 N-HLs were <10% of all other N-HLs, thus offering a possible explanation as to their lack of detection in previous studies. The chiral separations of all 18 N-HLs derivatives were accomplished by the complementary GC-MS/MS and LC-MS/MS methods. The limit of detection for LC-MS/MS method was as low as 1 ppb. The limit of detection for the GC-MS/MS method was found to be one to three orders of magnitude higher than the LC-MS/MS method. Due to the high extraction recovery and a preconcentration factor of 100, concentrations as low as 10 ppt can be detected by LC-MS/MS in biological samples. The LC-MS/MS approach provided greater enantioselectivity for the larger, more hydrophobic N-HLs while GC-MS/MS provided better enantioselectivity for the smaller N-HLs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Tryptophan (TRP) and its metabolites exhibit significant biological effects and are strongly associated with age-related disease and mortality. However, reports on quantitatively analyzing these metabolites in older individuals are not available. We used ultra-high-performance liquid chromatography-tandem mass spectrometry to optimize and validate a method for isotope dilution analysis of TRP metabolites in older individuals. The targeted analytes are TRP, serotonin or 5-hydroxytryptamine, kynurenine, kynurenic acid, xanthurenic acid, indole-3-acetic acid, indole-3-propionic acid, and tryptamine. The serum sample was purified using solid-phase extraction and was separated on a Waters HSS T3 column (100 mm × 2.1 mm, 1.8 μm). The analytes were detected in the multiple reaction monitoring mode under positive ionization. TRP was confirmed and measured after being diluted 100 times. This method exhibited satisfactory linearity (r > 0.99). The intrabatch and interbatch accuracies (85.7-114%) and precisions (<15%) were acceptable. The standard-normalized matrix effects ranged from 51.6 to 145%. This method was successfully applied to a cohort of 1021 older Chinese individuals, and this study may enable further understanding of the metabolic phenotypes associated with TRP in other populations., (© 2022 John Wiley & Sons Ltd.)

Endocannabinoids (eCBs) are a family of lipid molecules with important regulatory function in the brain and immune system. The two well-studied eCBs are arachidonic acid derivatives, N-arachidonoylethanolamine (AEA) and 2-arachidonoylglycerol (2-AG). Currently one of the most important methods for quantitative analysis of eCBs and related lipids from biological matrices is liquid chromatographic separation coupled with tandem mass spectroscopy (LC-MS/MS) owing to its high sensitivity and selectivity, as well as no derivatization procedures needed. Here we describe pretreatment procedures using solid-phase extraction for tissue sampling and an in vivo brain microdialysis approach prior to LC-MS/MS analysis, followed by detailed steps of LC-MS/MS analytic method to demonstrate the potential and application of this method in quantification of eCBs and congeners from various biological matrices., (© 2023. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Cell surface proteins, including transmembrane and other surface-anchored proteins, play a key role in several critical cellular processes and have a strong diagnostic value. The development of quick and robust experimental methods remains vital for the accurate and comprehensive characterization of the cell surface subproteome of individual cells. Here we present a high-throughput technique which relies on the biotinylation of the accessible primary amino groups in the extracellular segments of the proteins, using HL60 as a model cell line. Several steps of the method have been thoroughly optimized to capture labeled surface proteins selectively and in larger quantities. These include the following: improving the efficiency of the cell surface biotinylation; reducing the endogen protease activity; applying an optimal amount of affinity column and elution steps for labeled peptide enrichment; and examining the effect of various solid-phase extraction methods, different HPLC gradients, and various tandem mass spectrometry settings. Using the optimized workflow, we identified at least 1700 surface-associated individual labeled peptides (~6000-7000 redundant peptides) from the model cell surface in a single nanoHPLC-MS/MS run. The presented method can provide a comprehensive and specific list of the cell surface available protein segments that could be potential targets in various bioinformatics and molecular biology research.

Organophosphate triesters are compounds widely used in industries and are ubiquitous in the environment, where they can be transformed into organophosphate diesters. Some organophosphate diesters are also used by industry. Several studies suggest organophosphate diesters can have toxic effects for reproduction, and hazardous and mutagenic properties. Due to the impact these compounds can have on marine biota and human beings through the consumption of fish and shellfish, it is necessary to study their presence in widely consumed seafood species. We therefore developed an analytical method for determining six of the most common organophosphate diesters in seafood. The procedure is based on the Quick, Easy, Cheap, Effective, Rugged and Safe extraction method and a solid phase extraction clean-up, followed by liquid chromatography coupled to high-resolution mass spectrometry. The method was optimised and validated for seafood with different lipid content, providing satisfactory relative recoveries (from 89 to 138%) and limits of detection (1.0-50 ng g -1 dry weight), as well as repeatability values (RSD% ( n = 5 , 100 ng g -1 (dry weight)) lower than 15%. Eight seafood species were analysed using this method and two organophosphate diesters were detected and quantified in all the samples, demonstrating the suitability of the method.

A novel HPLC-ESI-MS/MS method for simultaneous gonadotropin-releasing hormone (GnRH) analogs and somatostatin analog quantitation was developed and validated. The developed method was successfully applied to pharmacokinetic studies. The sample preparation process included solid-phase extraction (SPE). Effective chromatographic separation of the analytes and internal standard (dalargin) was achieved with a C18 column, using a gradient elution with two mobile phases: 0.1% v / v formic acid (aqueous solution) and 0.1% v / v formic acid (acetonitrile solution). The linearity of the method was demonstrated within a concentration range of 0.5-20 ng/mL, with correlation coefficients between 0.998-0.999 for goserelin, buserelin, triptorelin, and octreotide, respectively. The relative standard deviation (RSD, %) values for method accuracy and precision did not exceed 20% at the lower level of quantitation (LLOQ) or 15% at other concentration levels.

UV-induced formation of photoproducts in DNA is a major initiating event of skin cancer. Consequently, many analytical tools have been developed for their quantification in DNA. In the present work, we extended our previous liquid chromatography-mass spectrometry method to the quantification of the short DNA fragments containing photoproducts that are released from cells by the repair machinery. We designed a robust protocol including a solid-phase extraction step (SPE), an enzymatic treatment aimed at releasing individual photoproducts, and a liquid chromatography method combining on-line SPE and ultra-high-performance liquid chromatography for optimal specificity and sensitivity. We also added relevant internal standards for a better accuracy. The method was validated for linearity, repeatability, and reproducibility. The limits of detection and quantification were found to be in the fmol range. The proof of concept of the use of excreted DNA repair products as biomarkers of the genotoxicity of UV was obtained first in in vitro studies using cultured HaCat cells and ex vivo on human skin explants. Further evidence was obtained from the detection of pyrimidine dimers in the urine of human volunteers collected after recreational exposure in summer. An assay was designed to quantify the DNA photoproducts released from cells within short fragments by the DNA repair machinery. These oligonucleotides were isolated by solid-phase extraction and enzymatically hydrolyzed. The photoproducts were then quantified by on-line SPE combined with UHPLC-MS/MS with isotopic dilution., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

Antimicrobial agents are essential to protect human and animal health. During the coronavirus disease 2019 pandemic, antimicrobials such as cephalosporins were widely used as prophylactics and to prevent bacterial co-infection. Undoubtedly, the prevalence of antibiotics in the aquatic environment will ultimately affect the degree of resistance against these bacteria in animals and the environmental systems. In order to monitor 16 cephalosporins in the aquatic environment, we developed a new liquid chromatography-tandem mass spectrometry method that functioned simultaneously under positive and negative electrospray ionization switching modes. The chromatographic separation has been implemented using a pentafluorophenyl propyl column kept at 40°C. The limits of detection and quantitation for the studied cephalosporins ranged from (8 × 10 -4 ) to (7.11 × 10 -2 ) ng/ml and from (2.61 × 10 -3 ) to (2.37 × 10 -1 ) ng/ml, respectively. The percent extraction efficiency (apparent recovery) and relative standard deviations for the analyzed cephalosporins ranged from 61.69% to 167.67% and 2.45% to 13.48%, respectively. The overall findings showed that the effluent from the wastewater treatment plants that receive wastewater from pharmaceutical factories had a higher detected amount of cephalosporins than that of domestic sewage. Moreover, seven cephalosporins, including cefuroxime, ceftazidime, cefradine, cefprozil, cefixime, cefalexin, and cefadroxil (0.68-105.45 ng/L) were determined in the aquatic environment., (© 2022 Wiley-VCH GmbH.)

Prostanoids are potent lipid mediators involved in a wide variety of physiological functions like blood pressure regulation or inflammation as well as cardiovascular and malign diseases. Elucidation of their modes of action is mainly carried out in pre-clinical animal models by quantifying prostanoids in tissues of interest. Unfortunately, prostanoids are prone to post-mortem artifact formation and de novo synthesis can already be caused by external stimuli during the euthanasia of animals like prolonged hypercapnia or ischemia. Therefore, this study investigates the suitability and impact of fast cervical dislocation for the determination of prostanoids (6-keto-PGF 1α , TXB 2 , PGF 2α , PGD 2 , PGE 2 ) in seven tissues of mice (spinal cord, brain, sciatic nerve, kidney, liver, lung, and spleen) to minimize time-dependent effects and approximate physiological concentrations. Tissues were dissected in a standardized sequence directly or after 10 min to investigate the influence of dissection delays. The enzyme inhibitor indomethacin (10 µM) in combination with low processing temperatures was employed to preserve prostanoid concentrations during sample preparation. Quantification of prostanoids was performed via LC-MS/MS. This study shows, that prostanoids are differentially susceptible to post-mortem artifact formation which is closely connected to their physiological function and metabolic stability in the respective tissues. Prostanoids in the brain, spinal cord, and kidney that are not involved in the regulatory response post-mortem, i.e. blood flow regulation (6-keto-PGF 1α , PGE 2 , PGF 2α ) showed high reproducibility even after dissection delay and could be assessed after fast cervical dislocation if prerequisites like standardized pre-analytical workflows with immediate dissection and inhibition of residual enzymatic activity are in place. However, in tissues with high metabolic activity (liver, lung) more stable prostanoid metabolites should be used. Moreover, prostanoids in the spleen were strongly affected by dissection delays and presumably the method of euthanasia itself., Competing Interests: Declaration of Competing Interest None, (Copyright © 2022 Elsevier Inc. All rights reserved.)

There has been a rising concern regarding the harmful impact of biotoxins, source of origin, and the determination of the specific type of toxin. With numerous reports on their extensive spread, biotoxins pose a critical challenge to figure out their parent groups, metabolites, and concentration. In that aspect, liquid chromatography-mass spectrometry (LC-MS) based analysis paves the way for its accurate identification and quantification. The biotoxins are ideally categorized as phytotoxins, mycotoxins, shellfish-toxins, ciguatoxins, cyanotoxins, and bacterial toxins such as tetrodotoxins. Considering the diverse nature of biotoxins, both low-resolution mass spectrometry (LRMS) and high-resolution mass spectrometry (HRMS) methods have been implemented for their detection. The sample preparation strategy for complex matrix usually includes "QuEChERS" extraction or solid-phase extraction coupled with homogenization and centrifugation. For targeted analysis of biotoxins, the LRMS consisting of a tandem mass spectrometer operating in multiple reaction monitoring mode has been widely implemented. With the help of the reference standard, most of the toxins were accurately quantified. At the same time, the suspect screening and nontarget screening approach are facilitated by the HRMS platforms during the absence of reference standards. Significant progress has also been made in sampling device employment, utilizing novel sample preparation strategies, synthesizing toxin standards, employing hybrid MS platforms, and the associated data interpretation. This critical review attempts to elucidate the progress in LC-MS based analysis in the determination of biotoxins while pointing out major challenges and suggestions for future development., (© 2021 John Wiley & Sons Ltd.)

Vancomycin is a glycopeptide antibiotic used to treat infections caused by Gram-positive bacteria. Due to the narrow therapeutic index of vancomycin, it is necessary to develop a sensitive and reliable analytical method to monitor the drug concentration in plasma. A novel method based on surface molecularly imprinted solid-phase extraction combined with liquid chromatography-tandem mass spectrometry for the determination of vancomycin in plasma sample was developed. The plasma sample was cleaned up through the solid-phase extraction process before the analysis. The calibration standard of vancomycin in plasma ranged between 1 and 100 ng/mL, and the correlation coefficient (r) was 0.9993. The average recoveries were from 94.3 to 104.0%, and the precision was less than 10.5%. The limit of detection and limit of quantification were 0.5 ng/mL and 1 ng/mL, respectively. The method validated was successfully used for the detection of vancomycin in mice after oral administration., (© 2022. The Author(s), under exclusive licence to The Japan Society for Analytical Chemistry.)

Oxycodone (OXY) is classified as a "strong opioid" in the World Health Organization system of cancer pain treatment. However, OXY also causes severe adverse reactions, such as respiratory depression. Thus, in order to adjust the dosage of OXY for well-managed pain relief with less toxicity, we tried establishing and validating a system for measuring plasma concentrations of OXY using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Human pooled plasma samples containing OXY diluted with 0.1% formic acid solution and internal standard (papaverine) were used for solid-phase extraction. The eluents were injected into LC-MS/MS with Unison UK-Silica column (100 × 2 mm, 3 μm, Imtakt). Mobile phase was a mixture of 1 mM ammonium formate solution and acetonitrile containing 0.1% formic acid (50:50). OXY in plasma could be measurable with good linearity in a concentration range of 2-100 ng/ml by using 100 μl of plasma within 4 min. Relative standard deviations of all validation results were within ±15%. These results suggest that our established method using LC-MS/MS to measure OXY in plasma would be useful to adjust the dosage of OXY in order to obtain its efficacy and to avoid its adverse reactions., (© 2022 The Authors. Neuropsychopharmacology Reports published by John Wiley & Sons Australia, Ltd on behalf of The Japanese Society of Neuropsychopharmacology.)

IWR-1-endo, a small molecule that potently inhibits the Wnt/β-catenin signaling pathway by stabilizing the AXIN2 destruction complex, can inhibit drug efflux at the blood−brain barrier. To conduct murine cerebral microdialysis research, validated, sensitive, and reliable liquid chromatography−tandem mass spectrometry (LC-MS/MS) methods were used to determine IWR-1-endo concentration in the murine plasma and brain microdialysate. IWR-1-endo and the internal standard (ISTD) dabrafenib were extracted from murine plasma and microdialysate samples by a simple solid-phase extraction protocol performed on an Oasis HLB µElution plate. Chromatographic separation was executed on a Kinetex C18 (100A, 50 × 2.1 mm, 4 µm particle size) column with a binary gradient of water and acetonitrile, each having 0.1% formic acid, pumped at a flow rate of 0.6 mL/min. Detection by mass spectrometry was conducted in the positive selected reaction monitoring ion mode by monitoring mass transitions 410.40 > 344.10 (IWR-1-endo) and 520.40 > 307.20 (ISTD). The validated curve range of IWR-1-endo was 5−1000 ng/mL for the murine plasma method (r2 ≥ 0.99) and 0.5−500 ng/mL for the microdialysate method (r2 ≥ 0.99). The lower limit of quantification (LLOQ) was 5 ng/mL and 0.5 ng/mL for the murine plasma and microdialysate sample analysis method, respectively. Negligible matrix effects were observed in murine plasma and microdialysate samples. IWR-1-endo was extremely unstable in murine plasma. To improve the stability of IWR-1-endo, pH adjustments of 1.5 were introduced to murine plasma and microdialysate samples before sample storage and processing. With pH adjustment of 1.5 to the murine plasma and microdialysate samples, IWR-1-endo was stable across several tested conditions such as benchtop, autosampler, freeze−thaw, and long term at −80 °C. The LC-MS/MS methods were successfully applied to a murine pharmacokinetic and cerebral microdialysis study to characterize the unbound IWR-1-endo exposure in brain extracellular fluid and plasma.

Monitoring the glycolysis pathway remains an analytical challenge as most metabolites involved are sugar phosphates. Structural similarity, instability, high polarity, and rich negative charges of sugar phosphates make LC-MS based analysis challenging. Here, we developed an improved workflow integrating uniformly 13 C-labeled yeast metabolite extract, TiO 2 -based enrichment, differential stable isotope labeling phosphate methylation, porous graphic carbon column, and selected reaction monitoring acquisition. Uniformly 13 C labeled yeast metabolite extract was used as internal standards while differential stable isotope labeled sugar phosphates worked as calibrants. The established method was validated in human plasma, platelet and cultured HeLa cells. The limits of quantification ranged between 0.25 and 0.54 pmol on column. The method was adapted and its applicability tested for human platelets in which activation with collagen-related peptide (CRP) clearly showed the upregulation of some SPx metabolites. The results document that this newly established method can be successfully used to monitor glycolysis in different biological samples. As an extension, more phosphorylated and carboxylated metabolites from the central carbon metabolism (pentose phosphate cycle, TCA cycle) were tested as well. This method showed superior performance, especially for multiple phosphorylated and carboxylated metabolites. For quantitative purpose, the concept of SPx in three sets ( 12 C-analytes, U- 13 C-IS, deuterated calibrants) has the potential to be adapted for more anionic metabolites., (Copyright © 2022 Elsevier B.V. All rights reserved.)

It is meaningful for drug discovery to discover lead compounds with specific skeletons from medicinal herbs. Screening bioactive compounds with specific skeletons by a simple and rapid strategy is still a challenging task. Solid-phase extraction (SPE) is a simple and time-saving technique in the laboratory and is often used in the concentration of natural products. It is attractive to apply the SPE in the screening of bioactive compounds with specific skeletons. To achieve this goal, SPE with an enzyme activity (EA) switch combined with mass spectrometry analysis was first proposed. The screening of benzoic acid-derived neuraminidase (NA) inhibitors from the root cortex of Paeonia suffruticosa Andrews (CPSA) was used as an example. The NA and crude extract of CPSA were incubated to form a sample solution. Subsequently, the sample was separated, detected, and collected by the SPE with an EA switch. When the detected values reduced significantly, the EA switch was triggered, and the collection was stopped. The collected eluents were treated for LC-MS/MS analysis. Finally, combining diagnostic ions and mass spectrometry data, two benzoic acid NA inhibitors were successfully screened from CPSA. In this study, the separation, detection, and collection were performed on one instrument system. Compared with the traditional isolation strategy, this strategy with the simpler operation and higher experimental efficiency could be an effective tool for the rapid screening of lead compounds with specific skeletons., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Xiaoer Huanglong Granule is the only Chinese Patent Medicine widely used for treating attention deficit hyperactivity disorder. However, not much is known about the bioactive components and pharmacokinetics of Xiaoer Huanglong Granule even after it was successfully introduced into clinical use. This study analyzed the components in the medication and rat plasma after oral administration with the help of the UNIFI platform and Masslynx. A total of 119 and 37 components were detected in the medication and plasma, respectively, using an ultra-performance liquid chromatography-tandem mass spectrometer. We established a rapid and sensitive simultaneous determination of one triterpene saponin, three monoterpene glycosides, and three lignans in rat plasma by solid-phase extraction. The determination was accomplished within 7.50 min via gradient elution. The values of the lower limit of quantitation were validated at 0.08 ng/ml for tenuifolin, 0.8 ng/ml for lactiflorin, 1.828 ng/ml for albiflorin, 2 ng/ml for paeoniflorin, gomisin B, and gomisin D, 10 ng/ml for schisandrin. The results from validations of other methods were all acceptable (relative standard deviation ≤ 14.94%). This is the first report on the identification and pharmacokinetics studies of components in Xiaoer Huanglong Granule. Moreover, the pharmacokinetic behavior of lactiflorin was studied for the first time., (© 2022 Wiley-VCH GmbH.)

In the current study, a novel kind of mixed-mode hydrophobic/hydrophilic hybrid silica material has been developed for the solid-phase extraction of hydrophobic and hydrophilic illegal additives from food samples. A hydrophobic hybrid silica material was first prepared by the sol-gel method with tetraethoxysilane, 3-aminopropyltriethoxysilane, and dimethyloctadecyl-[3-(trimethoxysilyl)propyl] ammonium chloride (DTSACl) as precursors. Subsequently, the hydrophobic hybrid silica material was activated by glutaraldehyde, followed by the covalent immobilization of polyethyleneimine (PEI). PEI and the octadecyl group of DTSACl produced the hydrophilic/hydrophobic features of the hybrid silica material. The developed material was characterized by scanning electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, solid-state nuclear magnetic resonance, zeta potential analyzer, and laser diffraction particle size analyzer, then applied as a hydrophobic and hydrophilic sorbent for the solid-phase extraction (SPE) of benzodiazepines from ginseng amino acid oral liquid as well as melamine and cyromazine from powdered milk, followed by RPLC/HILIC-MS/MS analysis. The composition and volumes for SPE loading and elution solutions were optimized in detail. Coupled with RPLC/HILIC-MS/MS, the proposed method provided satisfactory linearity in the range from 0.9-3.2 µg kg -1 to 100-250 µg kg -1 with the coefficients of determination higher than 0.99. The limits of detection ranged from 0.3 to 1.0 µg kg -1 , and the recoveries ranged from 81.1% to 109.0% with the relative standard deviations less than 8.5% (n = 3). This report offers a new mixed-mode hydrophobic/hydrophilic hybrid silica material to extract trace hydrophobic and hydrophilic additives from complex samples., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

Organophosphate esters (OPEs) and their diester metabolites have been frequently found in various environmental matrices and regarded as emerging environmental pollutants, whereas data on their occurrence in foods and human matrices are still limited. In this study, a novel and simple procedure was developed to simultaneously determine 14 OPEs and 6 diester metabolites in dairy products and human milk. After enzymatic hydrolysis by β-glucuronidase/arylsulfatase, a freeze-dried milk sample was extracted with acetonitrile and purified by solid-phase extraction. Subsequently, all target compounds were determined by HPLC-ESI-MS/MS. Linearity, limits of detection (LODs), recovery, precision, and matrix effects of the proposed methodology were validated, and the parameters of HPLC-ESI-MS/MS were optimized. LODs for OPEs and their diester metabolites were from 0.001 to 0.02 ng/mL, and limits of quantification (LOQs) were 0.01-0.3 ng/mL. Average recoveries at two spiked levels ranged between 67.3 and 121%, with relative standard deviation lower than 20.7%. A test for matrix effects showed that most analytes presented signal suppression, and isotopically labeled ISs were essential for compensating for the matrix effects. Finally, OPEs and their metabolites both showed high detecting frequencies in real samples, which indicated that these emerging pollutants were ubiquitous in foods and the human body, and the impact of the diester metabolites on population exposure must be included in exposure assessment., (© 2022. Springer-Verlag GmbH Germany, part of Springer Nature.)

Liposome encapsulating cytarabine (CYT) and daunorubicin (DNR) is applied for treating Acute Myeloid Leukemia (AML) patients. To evaluate and compare relationship between the pharmacokinetics of free drug (drug which is not entrapped in liposomes) and liposome-encapsulated drug and the toxicity/efficacy, it is crucial to have trustworthy methods for separating the free and the encapsulated of the drug. In this study, methods were developed and validated to isolate and measure the free DNR/CYT (F-DNR/CYT), the encapsulated DNR/CYT (E-DNR/CYT) and the total DNR/CYT (T-DNR/CYT) in rat plasma. The methods involved solid-phase extraction (SPE) using reverse adsorbents for separating the F-DNR and E-DNR, SPE using cation exchange adsorbents for separating the E-CYT, ultrafiltration for isolating the F-CYT and protein precipitation (PPT) for releasing the T-DNR and T-CYT totally from the liposomal forms. The analytes were subsequently quantified on ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) individually with multiple reaction monitoring (MRM) mode using positive electrospray ionization (ESI). The calibration curves showed good linear relationships over the concentration range of 0.22-44 μg/mL for E-DNR and T-DNR, 2-1000 ng/mL for F-DNR, 0.5-100 μg/mL for E-CYT and T-CYT, 4-2000 ng/mL for F-CYT respectively. For all the analytes, the within-and between-run precisions were less than13.6% and the accuracies (in terms of RE%) were within -12.5%. Besides, extraction recovery, matrix effect, dilution integrity and stability were also assessed. The methods were successfully applied to investigate the pharmacokinetics in Sprague-Dawley rats following i.v. administration liposomal formulation., (Copyright © 2022. Published by Elsevier B.V.)

The present study firstly aimed at developing a multi-residue method to identify and quantify 38 veterinary antibiotics (belonging to five different classes) not only for raw swine wastewater but also for wastewater differently treated by different units. The proposed method is based on a solid-phase extraction procedure and ultra high performance liquid chromatography with mass spectrometry. For sample preparation, the optimal loading sample volume was selected as 50 mL, the pH of which was adjusted to approximately 3.0 using formic acid. Then 0.1 g/L ethylenediaminetetraacetic acid disodium salt was added. The recovery rates for different types of wastewaters were in the range of 35.94-124.51% and the relative standard deviations were in the range of 0.36-14.62%. All the matrix standard curves exhibited high linearity (0.9956-0.9999). The matrix effects for the target antibiotics ranged from -61.73 to +148.75%. To ensure the practicality of the method, we performed the detection of the actually added concentration to determine method detection limits and quantitation limits. The quantitation limits of most of the target antibiotics were 0.04 μg/L, except for spiramycin (0.1 μg/L) and roxithromycin (0.2 μg/L). This optimized and validated method was applied to analyze antibiotic residues in swine water samples from four swine farms., (© 2022 Wiley-VCH GmbH.)

An efficient, reliable, and sensitive multiclass analytical method has been expanded to simultaneously determine 15 human pharmaceutical residues in fish and shrimp tissue samples by ultra-high-performance liquid chromatography-tandem mass spectrometry. The investigated compounds comprise ten classes, namely, analgesic, antibacterial, anticonvulsant, cardiovascular, fluoroquinolones, macrolides, nonsteroidal anti-inflammatory, penicillins, stimulant, and sulfonamide. A simple liquid extraction procedure based on 0.1% formic acid in methanol was developed. Chromatographic conditions were optimized, and mobile phase A was 0.1% ammonium acetate, and mobile phase B was acetonitrile. The mobile phase's gradient program was as follows: 0-2 min, 15% B; 2-5 min, linear to 95% B; 5-10 min, 95% B; and 10-12 min. The limits of detection were from 0.017 to 1.371 μg/kg, while a quantification range was measured from 0.051 to 4.113 μg/kg. Finally, amoxicillin, azithromycin, caffeine, carbamazepine, ciprofloxacin, clarithromycin, diclofenac, erythromycin, furosemide, ibuprofen, ketoprofen, naproxen, sulfamethoxazole, tetracycline, and triclosan were quantifiable in fish and shrimp samples., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

In this work, Hexagonal Mesoporous Silica (HMS) and Santa Barbara Amorphous-15 (SBA-15) mesostructured silicas were synthesized and functionalized with sulfonic acid groups. The materials (HMS-SO3− and SBA-15-SO3−) were evaluated as strong cation exchange sorbents for sample extract clean-up, by solid phase extraction (SPE) and dispersive solid phase extraction, to determine atropine (At) and scopolamine (Sc) in commercial culinary aromatic herbs. Under optimized conditions, 0.25 g of sample was subject to solid−liquid extraction with acidified water (pH 1.0), and good recovery percentages were achieved for At and Sc using 75 mg of HMS-SO3− in SPE as the clean-up stage, prior to their determination by HPLC-MS/MS. The proposed method was validated in a thyme sample showing recoveries in the range of 70−92%, good linearity (R2 > 0.999), adequate precision (RSD ≤ 14%) and low limits (MDL 0.8−2.2 µg/kg and MQL 2.6−7.2 µg/kg for both analytes). Sixteen aromatic herbs samples (dried thyme, basil and coriander leaves) were analysed and At was found in fourteen samples over an interval of <5−42 μg/kg, whereas Sc was found in three of the sixteen samples studied (between <5−34 μg/kg). The amount of At and Sc found in some analysed samples confirms the importance of setting maximum levels of At and Sc in culinary aromatic herbs.

Furosemide is a diuretic drug used to increase urine flow in order to reduce the amount of salt and water in the body. It is commonly utilized to treat preterm infants with chronic lung disease of prematurity. There is a need for a simple and reliable quantitation of furosemide in human urine. We have developed and validated an ultra-high performance liquid chromatography-tandem mass spectrometry method for furosemide quantitation in human urine with an assay range of 0.100-50.0 μg/ml. Sample preparation involved solid-phase extraction with 10 μl of urine. Intra-day accuracies and precisions for the quality control samples were 94.5-106 and 1.86-10.2%, respectively, while inter-day accuracies and precision were 99.2-102 and 3.38-7.41%, respectively. Recovery for furosemide had an average of 23.8%, with an average matrix effect of 101%. Furosemide was stable in human urine under the assay conditions. Stability for furosemide was shown at 1 week (room temperature, 4, -20 and -78°C), 6 months (-78°C), and through three freeze-thaw cycles. This robust assay demonstrates accurate and precise quantitation of furosemide in a small volume (10 μl) of human urine. It is currently being implemented in an ongoing pediatric clinical study., (© 2021 John Wiley & Sons, Ltd.)

Efficient and reproducible measurements of multiple polycyclic aromatic hydrocarbon (PAH) metabolites in urinary samples are required to evaluate the complex health effects of PAH exposure. Here, we demonstrate a highly practical, automated off-line solid-phase extraction (SPE) of deconjugated hydroxylated PAHs followed by LC-MS/MS to simultaneously measure eight mono-hydroxylated PAH compounds: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 1-hydroxyphenanthrene, 2&3-hydroxyphenanthrene, 4-hydroxyphenanthrene and 1-hydroxypyrene. Initially, we observed low recovery rates (e.g., 16% for 1-hydroxypyrene) when using previously published methods. We optimized the procedure by choosing polymeric absorbent-based cartridges, automating the sample loading step by diluting samples with 15% methanol/sodium acetate, and most importantly, replacing acetonitrile with methanol as the eluting solvent. Optimized sample preparation has improved the recovery rates to more than 69% for analytes of interest. This improvement led to higher method sensitivity and detection frequency, especially for 1-hydroxypyrene, in all of 100 urine samples collected in the New York City site of the Legacy Girls Study. The limits of detection ranged from 7.6 pg/mL to 20.3 pg/mL using 1 mL of urine, compared to the 2 mL required in CDC, method 09-OD. The average coefficients of variance of quality control samples (n = 60) ranged between 7 and 21%; variance of repeated measurements (n = 45) was less than 10%. This efficient and reliable method for measuring PAH metabolites will greatly benefit epidemiology studies and biomonitoring programs., (Copyright © 2022 Elsevier B.V. All rights reserved.)

This paper describes an analytical approach based on solid-phase extraction (SPE) followed by analysis using liquid and gas chromatography coupled to mass spectrometry detectors for a determination of 18 organic UV filters from water samples. Extraction method parameters were optimized: 250 ml of water sample loaded on Chromabond C18 cartridges after adjustment to pH 4 and then eluted with acetonitrile. The mobile phase and the parameters of the mass spectrometer, as well as those of the ionization source, were tested to enhance detection sensitivity. During method validation, the extracted target compounds showed good recoveries (> 68%) with acceptable values in terms of repeatability (RSD r ) and reproducibility (RSD R ), where relative standard deviations values were lower than 20%. The validated method was applied to 10 water samples collected from different swimming pools located in Lebanon from which eight UV filters among the eighteen targets compounds were detected at concentrations ranged between 1 and 2526 µg L -1 . The most detected compounds were padimate-O (OD-PABA) and octocrylene (OCR). This study represents the first available data on the occurrence of UV filter residues in Lebanese swimming pool opening hence future perspectives and insights to evaluate their degradation by-products and their toxicity on human health and marine ecosystem., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

In this work, an integrated sample-pretreatment strategy for the separation and enrichment of microplastics and primary aromatic amines from the migration of teabag was developed. The migration solution of teabag was passed through a homemade device. The microplastics were firstly captured by a silver membrane, and then the primary aromatic amines were enriched by a solid-phase extraction column. The microplastics migrated from teabag were detected by attenuated total reflection-Fourier transform infrared spectrometer and Raman spectroscopy. The data showed the character, the number of particles, area ratio, and morphology of microplastics migrated from the teabag. Subsequently, after the enrichment procedure, a sensitive analytical method for primary aromatic amines was established followed by ultra-high performance liquid chromatography-tandem mass spectrometry. The method showed wide linear ranges with R 2 greater than 0.9915, low limits of detection (2-18 ng/L), and low limits of quantification (8-50 ng/L). The developed method was adopted to analyze microplastics and primary aromatic amines migrated from nylon and polyethylene terephthalate teabag under different temperatures and times. The integrated sample-pretreatment strategy displayed promising potentials in the one-step preparation of the microplastics and hazardous molecules in the sample of environment and food security., (© 2021 Wiley-VCH GmbH.)

Inositol phosphates belong to a family of structurally diverse signaling molecules playing crucial role in Ca 2+ release from intracellular storage vesicles. There are many possibilities of phosphorylation, including their degree and position. Inositol (1,4,5) trisphosphate has been well recognized as the most important second messenger among this family. It remains a challenge to analyse the entire inositol phosphate metabolite family due to its structural complexity, high polarity, and high phosphate density. In this study, we have established an improved UHPLC-ESI-MS/MS method based on a differential isotope labelling methylation strategy. An SPE extraction kit composed of TiO2 and PTFE filter was employed for sample preparation which provided good extraction performance. Samples were methylated (light label) to neutralize the phosphate groups and give better performance in liquid chromatography. Regioisomers and inositol phosphates differing in their number of phosphate residues were successfully separated after optimization on a core-shell cholesterylether-bonded RP-type column (Cosmocore 2.6Cholester) using methanol as organic modifier. Triple quadrupole MS detection was based on selected reaction monitoring (SRM) acquisition with characteristic fragments. Stable isotope labeling methylation was performed to generate internal standards (heavy label). Limits of quantification from 0.32 to 0.89 pmol on column was achieved. This method was validated to be suitable for inositol phosphate profiling in biological samples. After application in cultured HeLa cells, NIST SRM1950 plasma, and human platelets, distinct inositol profiles were obtained. This newly established method exhibited improved analytical performance, holding the potential to advance the understanding of inositol phosphate signaling., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In this study, we combined ultra-high performance liquid chromatography with tandem mass spectrometry to establish a quick, easy, cheap, effective, rugged, and safe method of detecting 21 target antibiotics in agricultural soil samples. Antibiotics were extracted with mixed solvents consisting of ethylenediaminetetraacetic acid disodium salt dihydrate and phosphoric acid citric acid buffer and acetonitrile which were purified with octadecylsilyl as an adsorbent and anhydrous sodium sulfate as a desiccant. This method was able to effectively extract all of the target antibiotics from agricultural soils, with recovery efficiencies ranging from 55 to 108% and limits of detection between 0.09-0.68 μg/kg. We also validated this new method for selectivity, sensitivity, and reliability of detecting multiple antibiotics in 12 samples. Considering the potential environmental and public health effects of antibiotics in agricultural soils, our new method can help analyze the degree of antibiotic contamination and provide valuable information for soil quality and risk assessment., (© 2021 Wiley-VCH GmbH.)

An accurate and sensitive UPLC-MS/MS method was developed and validated for the simultaneous estimation of the newly developed combination of sacubitril and valsartan and the co-administered drugs nebivolol, chlorthalidone and esomeprazole in human plasma. Solid-phase extraction was conducted for the purification and extraction of the drugs from human plasma. Chromatographic separation was carried out on an Agilent SB-C 18 (1.8 μm, 2.1 × 50 mm) column using losartan as internal standard. Isocratic elution was applied using acetonitrile-0.1% formic acid in water (85: 15, v/v) as mobile phase. Detection was carried out using a triple-quadrupole tandem mass spectrometer using multiple reaction monitoring, at positive mode at m/z 412.23 → 266.19 for sacubitril, m/z 436.29 → 235.19 for valsartan, m/z 405.8 → 150.98 for nebivolol, m/z 346.09 → 198 for esomeprazole and a selected combination of two fragments m/z 423.19 → 207.14 and 423.19 → 192.2 for losartan (internal standard), and in negative ionization mode at m/z 337.02 → 190.12 for chlorthalidone. The method was linear over the concentration ranges 30-2,000 ng/ml for sacubitril, 70-2,000 ng/ml for valsartan, esomeprazole and chlorthalidone and 70-5,000 pg/ml for nebivolol. The developed method is sensitive and selective and could be applied for dose adjustment, bioavailability and drug-drug interaction studies., (© 2021 John Wiley & Sons, Ltd.)

A novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the rapid and sensitive enantioselective analysis of verapamil (VER) in rat plasma was developed and validated using new superficially porous silica isopropyl-cyclofructan 6 chiral column (LarihcShell-P, LSP). The isocratic mobile phase composed of acetonitrile: trifluoroacetic acid: 10 mM ammonium formate (100 : 0.1 : 0.1, v/v/v) at a flow rate of 0.3 mL/min was applied. Sulpride was utilized as the internal standard (IS). Positive multiple reaction monitoring (MRM) mode was used for mass spectrometry analysis, and the process of analysis was run for 5.2 min. The (S)-(-)- and (R)-(+)-VER enantiomers with the IS were extracted from plasma by using solid-phase extraction (SPE) procedure before the analysis. The C18 cartridge gave good recovery rates for both enantiomers without interference from plasma endogenous. The developed assay was successfully validated following the US-FDA guidelines. The method was linear over concentration ranges of 0.5-500 ng/mL (r 2 ≥ 0.997) for each enantiomer (plasma). The lower limits of quantification (LLOQ) for both isomers were 0.5 ng/mL. The intra- and inter-day relative standard deviations (RSD) were less than 8.7 % and the recoveries of (S)-(-)- and (R)-(+)-VER at three spiked levels of 1.5, 250.0 and 450.0 ranged from 92.0%-98.6%. The developed assay was effectively applied in monitoring the stereoselective pharmacokinetic study of VER enantiomers in rat plasma following oral administration of racemic VER. The pharmacokinetic parameters revealed that (S)-(-)-VER demonstrated prominently higher C max and AUC values than (R)-(+)-enantiomer. The newly developed approach is the first chiral LC-MS/MS for the quantification of (S)-(-)- and (R)-(+)-VER utilizing superficially porous silica isopropyl-cyclofructan 6 chiral column in rat plasma after SPE., Competing Interests: Declaration of Competing Interest The authors have declared no conflicts of interest., (Copyright © 2021 Elsevier B.V. All rights reserved.)

In vivo metabolite profiling of herbal medicines remains a challenge due to the complex chemical composition and drastic interference from biological matrix. In this study, a systematic strategy was established for comprehensive metabolite profiling of Danqi Tongmai (DQTM) tablet, a combination of salvianolic acids and notoginsenosides, in rats after oral administration. This strategy was composed of six steps. Firstly, the rat plasma and tissue samples were collected at multiple time points to increase the representativeness of samples. Secondly, different sample preparation methods were systematically investigated including protein precipitation, liquid-liquid extraction and solid-phase extraction to obtain superior extraction efficiency for both salvianolic acids and notoginsenosides. Thirdly, the MS acquisition method was optimized by splitting the full scan range into two separate segments to improve the detection capability for minor components. Fourthly, an extended polygonal mass defect filter (EP-MDF) model was constructed to filter potential metabolites of salvianolic acids and notoginsenosides, and remove large amounts of interference ions. Fifthly, ion intensity-based time point-staggered precursor ion list (IITPS-PIL) was generated to trigger more targeted MS/MS acquisition for potential metabolites at the highest concentration. Finally, the absorbed prototypes and metabolites were comprehensively characterized by reference standards and MS/MS fragmentation. The proposed strategy significantly improved the detection ability for trace prototypes and metabolites in vivo. A total of 370 components, including 94 prototypes (38 confirmed with reference standards) and 276 metabolites, were tentatively characterized in rat plasma and tissue samples after oral administration of DQTM. Collectively, this paper provided an applicable reference for comprehensive metabolite profiling of herbal medicines in complex biological samples., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Fosinopril diacid is an angiotensin converting enzyme inhibitor with efficient antihypertensive action. It is an active metabolic product formed in the body from hydrolysis of its prodrug Fosinopril. A sensitive, rapid method with high recovery for Fosinopril diacid from human plasma was developed. Solid-phase extraction technique employing Waters Oasis SPE cartridges gave clean samples with very high recovery of 97%. The analyte along with its internal standard (Benazepril hydrochloride) were chromatographed on an XTerra RP 8 column (4.6 × 50 mm, 5 μm) using methanol-ammonium acetate buffer (10 mm; 90:10, v/v) as the mobile phase. A triple quadrupole mass spectrometer equipped with electrospray ionization source operated in the negative ion mode was used for detection. Multiple reaction monitoring scan mode was used for monitoring the transitions from m/z 434.00 → 237.15 for Fosinopril diacid and m/z 423.10 → 174.00 for Benazepril hydrochloride. Beer-Lambert's law was obeyed in the range of 0.50-1,500.00 ng/ml (r = 0.9993). The stability of the drugs in human plasma and in stock solution was proved by performing stability tests as per US Food and Drug Administration guidelines. The method was successfully applied for a bioequivalence study of Fosinopril diacid in 36 healthy, adult, male volunteers under fasting conditions., (© 2020 John Wiley & Sons, Ltd.)

Medicinal plants are complex chemical systems containing thousands of secondary metabolites. The rapid classification and characterization of the components in medicinal plants using mass spectrometry (MS) remains an immense challenge. Herein, a novel strategy is presented for MS through the combination of solid-phase extraction (SPE), multiple mass defect filtering (MMDF) and molecular networking (MN). This strategy enables efficient classification and annotation of natural products. When combined with SPE and MMDF, the improved analytical method of MN can perform the rapid annotation of diverse natural products in Citrus aurantium according to the tandem mass spectrometry (MS/MS) fragments. In MN, MS2LDA can be initially applied to recognize substructures of natural products, according to the common fragmentation patterns and neutral losses in multiple MS/MS spectra. MolNetEnhancer was adopted here to obtain chemical classifications provided by ClassyFire. The results suggest that the integrated SPE-MMDF-MN method was capable of rapidly annotating a greater number of natural products from Citrus aurantium than the classical MN strategy alone. Moreover, SPE and MMDF enhanced the effectiveness of MN for annotating, classifying and distinguishing different types of natural products. Our workflow provides the foundation for the automated, high-throughput structural classification and annotation of secondary metabolites with various chemical structures. The developed approach can be widely applied in the analysis of constituents in natural products.

A micron-sized sorbent, Magn-Humic, has been prepared by humic acids pyrolysis onto silica-coated magnetite. The material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), thermogravimetric analysis (TGA), and Brunauer, Emmett, and Teller (BET) surface area measurements and applied for simultaneous magnetic solid-phase extraction (MSPE) of glucocorticoids, estrogens, progestogens, and androgens at ng mL -1 levels from human plasma followed by high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS). Due to the low affinity for proteins, steroids extraction was done with no need for proteins precipitation/centrifugation. As highlighted by a design of experiments, MSPE was performed on 250 µL plasma (after 1:4 dilution) by 50 mg Magn-Humic (reusable for eight extractions) achieving quantitative recovery and satisfying clean-up. This was improved by washing (2 mL 2% v / v formic acid) prior to analytes elution by 0.5 mL 1:1 v / v methanol-acetonitrile followed by 0.5 mL methanol; eluate reduction to 0.25 mL compensated the initial sample dilution. The accuracy was assessed in certified blank fetal bovine serum and in human plasma, gaining satisfactory recovery in the range 65-122%, detection limits in the range 0.02-0.3 ng mL -1 (0.8 ng mL -1 for 17-β-estradiol) and suitable inter-day precision (relative standard deviation (RSD) <14%, n = 3). The method was evaluated in terms of selectivity, sensitivity, matrix-effect, instrumental carry-over, and it was applied to human plasma samples.