Search Results (45)

Food safety concerns related to pesticide residues in fruits and vegetables have increased globally, particularly in regions where monitoring programs are scarce or inconsistent. This study provides the first multi-year evaluation of pesticide contamination and associated dietary risks in Cape Verde, an African island nation increasingly reliant on imported produce. A total of 570 samples of fruits and vegetables—both locally produced and imported—were collected from major markets across the country between 2017 and 2020 and analyzed using validated multiresidue methods based on gas chromatography coupled to Ion Trap mass spectrometry (GC-IT-MS/MS), and both gas and liquid chromatography coupled to triple quadrupole tandem mass spectrometry (GC-QqQ-MS/MS and LC-QqQ-MS/MS). Residues were detected in 63.9% of fruits and 13.2% of vegetables, with imported fruits showing the highest contamination levels and diversity of compounds. Although only one sample exceeded the maximum residue limits (MRLs) set by the European Union, 80 different active substances were quantified—many of them not authorized under the current EU pesticide residue legislation. Dietary exposure was estimated using median residue levels and real consumption data from the national nutrition survey (ENCAVE 2019), enabling a refined risk assessment based on actual consumption patterns. The cumulative hazard index for the adult population was 0.416, below the toxicological threshold of concern. However, when adjusted for children aged 6–11 years—taking into account body weight and relative consumption—the cumulative index approached 1.0, suggesting a potential health risk for this vulnerable group. A limited number of compounds, including omethoate, oxamyl, imazalil, and dithiocarbamates, accounted for most of the risk. Many are banned or heavily restricted in the EU, highlighting regulatory asymmetries in global food trade. These findings underscore the urgent need for strengthened residue monitoring in Cape Verde, particularly for imported products, and support the adoption of risk-based food safety policies that consider population-specific vulnerabilities and mixture effects. The methodological framework used here can serve as a model for other low-resource countries seeking to integrate analytical data with dietary exposure in a One Health context. Full article

Objectives: This study aimed to develop and validate a sensitive and reliable liquid chromatography–tandem mass spectrometry (LC-MS/MS) method for the quantification of flualprazolam and isotonitazene in serum samples to address critical gaps in forensic and clinical toxicology. Materials and Methods: A single-center validation study was conducted using serum samples spiked with analyte standards. Analytical parameters, including linearity, precision, recovery, the limit of detection (LOD), and the limit of quantification (LOQ), were evaluated in accordance with international guidelines. The LC-MS/MS method employed a Shimadzu Triple Quadrupole™ MS 8045 system with solid-phase extraction (SPE) for sample preparation. Results: The method exhibited high linearity for flualprazolam (r² = 0.997) and isotonitazene (r² = 0.999) over a concentration range of 1–100 ng/mL. The LODs were determined as 0.608 ng/mL and 0.192 ng/mL, and the LOQs were 1.842 ng/mL and 0.584 ng/mL for flualprazolam and isotonitazene, respectively. Recovery tests yielded results within the acceptable range of 70–120%. Flualprazolam demonstrated recovery rates of 98.0% and 97.0% at theoretical concentrations of 10 ng/mL and 50 ng/mL, respectively. In contrast, the isotonitazene recovery rates were slightly lower, measuring 75.5% at 10 ng/mL and 71.9% at 50 ng/mL, suggesting minor matrix effects that could influence its quantification. Precision analysis, including both repeatability and reproducibility, highlighted the reliability of the method. The %RSD values for flualprazolam were consistently below 7.07%, with mean concentrations closely aligning with theoretical values across fortification levels. For isotonitazene, the %RSD values remained below 6.24%, although recoveries at higher concentrations indicated potential challenges in matrix interaction. Conclusions: This validated LC-MS/MS method offers high sensitivity, precision, and recovery for detecting flualprazolam and isotonitazene in serum, filling a critical need in toxicological investigations. Further validation in other biological matrices is recommended to broaden its applicability. Full article

Oxytocin and cortisol (OXY and CORT) are hormones related to stress, cognitive, and social behaviors. Their detection is relevant to epidemiological studies aimed at investigating the effects of stressor factors on human life. The aim of this study was to develop and validate an assay for the measurement of OXY and CORT in saliva samples using liquid chromatography/tandem mass spectrometry (LC-MS/MS) in the presence of deuterated analogs. A 500 mL aliquot of oral fluid, obtained by the centrifugation of a chewed swab, was purified by solid-phase extraction. Analytes were then separated using C18 reversed-phase chromatography, subjected to positive electrospray ionization, and then quantified using a triple-quadrupole mass detector in multiple-reaction monitoring mode. The limits of quantification and the linear dynamic ranges were 2.0 × 10⁻³ and 0.5 nmol/L, and up to 1.0 × 10⁻¹ and 20 nmol/L for OXY and CORT, respectively. Inter- and intra-run precision, expressed as relative standard deviation, was <7%, and accuracy was within 93–104% of the theoretical concentrations. The evaluation of matrix effects showed that the use of internal standards controlled sources of bias. The high sensitivity of the method allowed the quantification of OXY and CORT in the salivary samples of both adults and children: levels of CORT ranged from 0.6 to 18.5 nmol/L, while OXY levels were two orders of magnitude lower (from 1.7 × 10⁻³ to 1.1 × 10⁻² nmol/L). To our knowledge, this is the first method that can analyze, in the same chromatographic run, both hormones in saliva samples. Full article

The aim of this study was to develop and validate a fast and sensitive bioanalytical method for the accurate quantification of fosfomycin concentrations in human prostatic tissue. The sample preparation method only required milligrams of tissue sample. Each sample was mixed with two times its weight of water and homogenized. A methanol solution that was three times the volume of the internal standard (fosfomycin-13C3) was added, followed by vortex mixing and centrifugation. After its extraction from the homogenized prostatic tissue, fosfomycin was quantified by means of a liquid chromatography–tandem mass spectrometry (LC-MS/MS) triple quadrupole system operating in negative electrospray ionization and multiple reaction monitoring detection mode. The analytical procedure was successfully validated in terms of specificity, sensitivity, linearity, precision, accuracy, matrix effect, extraction recovery, limit of quantification, and stability, according to EMA guidelines. The validation results, relative to three QC levels, were 9.9% for both the within-day and inter-day accuracy (BIAS%); 9.8% for within-day precision; and 9.9 for between-day precision. A marked matrix effect was observed in the measurements but was corrected by normalization with the internal standard. The average total recovery was high (approximatively 97% at the three control levels). The dynamic range of the method was 0.1–20 μg/g (R² of 0.999). Negligible carry-over was observed after the injection of highly concentrated samples. F in the sample homogenate extracts was stable at 10 °C and 4 °C for at least 24 h. In the tissue sample freeze–thaw experiments, a significant decrease in F concentrations was observed after only two cycles from −80 °C to room temperature. The novel method was successfully applied to measure fosfomycin in prostatic tissue samples collected from 105 patients undergoing prostatectomy. Full article

Ostarine is frequently misused as a selective androgen receptor modulator (SARM) in sports. Consequently, there is a pressing need for reliable and simple approaches to monitor its presence in biological systems. In this work, we developed a two-dimensional analytical method utilizing online solid-phase extraction (online-SPE) in conjunction with ultra-high-performance liquid chromatography and tandem mass spectrometry (triple quadrupole). This automated 2D separation approach is characterized by minimum manual steps in the sample preparation (only dilute-and-shoot), reflecting high sample throughput and the reliability of analytical data. It provides favorable performance parameters, including a limit of detection of 0.5 pg/mL, high accuracy (relative error = 1.6–7.5%), precision (relative standard deviation = 0.8–4.5%), and sensitivity. Additionally, it demonstrates excellent linearity (r² = 0.9999) in the calibration range of 0.05 to 25 ng/mL and robustness, with no carryover effects observed. This comparative study revealed a two-decadic-order-lower LOD of the SPE-UHPLC-MS/MS method to the corresponding UHPLC-MS/MS method and the lowest one in the group of currently published LC-MS methods. The World Anti-Doping Agency screening and confirmation criteria were met through the analysis of spiked urine samples from ten healthy volunteers. Accordingly, the proposed method is suitable for routine use in antidoping laboratories. Full article

Klebsiella pneumoniae (K. pneumoniae) is a multidrug-resistance Gram-negative organism responsible for carbapenem-resistant infections. These challenges have inspired studies on the use of natural products as alternatives to conventional drugs. The aim of this study was to analyze the antibacterial and antioxidant effects of Ficus carica L. (fig) branch extracts and to perform in vivo animal experiments to better understand the absorption mechanisms of the antibacterial components during the digestion process after oral administration. The antibacterial components of the fig branch extracts were analyzed via gas chromatography-mass spectrometry (GC-MS). An in vivo animal study and liquid chromatography-triple quadrupole-tandem mass spectrometry (LC-QQQ-MS/MS) analyses were performed to analyze the deacetylation reactions of the fig extracts after oral administration in mice. Ultimately, the antibacterial effects of the fig extracts increased with the fractional distillation time. The fig extracts showed excellent antibacterial effects against K. pneumoniae, as well as Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Pseudomonas aeruginosa (P. aeruginosa). The three antibacterial and antioxidant components of the fig extracts were revealed to be eugenol, acetyleugenol, and psoralen. Interestingly, in this study, we identified acetyleugenol in the phenolic compounds of the fig extract for the first time. Through in vivo animal testing, we observed the deacetylation reaction of acetyleugenol to eugenol in the fig extract as digestion proceeded in the internal organs of the mice after oral administration. The results of this study suggest the use of natural fig extract as an effective therapeutic and prophylactic antibacterial agent for inflammation-related infections with a wide variety of biomedical applications. Full article

Perilla seeds are essential functional foods and key ingredients in traditional medicine. Herein, we investigated the variation in phytochemical profiles and antioxidant activities of twelve different perilla seeds. The seeds showed significant variations in total phenolic and flavonoid contents ranging from 16.92 to 37.23 mg GAE/g (GAE, gallic acid equivalent) and 11.6 to 19.52 mg CAE/g (CAE, catechin equivalent), respectively. LC-QqQ-MS (liquid chromatography triple quadrupole tandem mass spectrometry)-based widely targeted metabolic profiling identified a total of 975 metabolites, including 68–269 differentially accumulated metabolites (DAMs). Multivariate analyses categorized the seeds into four groups based on the seed coat and leaf colors. Most key bioactive DAMs, including flavonoids (quercetin-3’-O-glucoside, prunin, naringenin, naringenin chalcone, butin, genistin, kaempferol-3-O-rutinoside, etc.), amino acids (valine, lysine, histidine, glutamine, threonine, etc.), and vitamins (B1, B3, B6, U, etc.) exhibited the highest relative content in PL3 (brown seed, purple leaf), PL1 (white seed, green-purple leaf), and PL4 (white seed, green leaf) groups, respectively. Meanwhile, key differentially accumulated phenolic acids showed a higher relative content in PL1 and PL4 than in other groups. Both seeds exhibited high antioxidant activities, although those of PL2 (brown seed, green leaf) group seeds were the lowest. Our results may facilitate the comprehensive use of perilla seeds in food and pharmaceutical industries. Full article

Marine biotoxins have posed a persistent problem along various coasts for many years. Coastal lagoons are ecosystems prone to phytoplankton blooms when altered by eutrophication. The Mar Menor is the largest hypersaline coastal lagoon in Europe. Sixteen marine toxins, including lipophilic toxins, yessotoxins, and domoic acid (DA), in seawater samples from the Mar Menor coastal lagoon were measured in one year. Only DA was detected in the range of 44.9–173.8 ng L⁻¹. Environmental stressors and mechanisms controlling the presence of DA in the lagoon are discussed. As an enrichment and clean-up method, we employed solid phase extraction to filter and acidify 75 mL of the sample, followed by pre-concentration through a C18 SPE cartridge. The analytes were recovered in aqueous solutions and directly injected into the liquid chromatography system (LC-MS), which was equipped with a C18 column. The system operated in gradient mode, and we used tandem mass spectrometry (MS/MS) with a triple quadrupole (QqQ) in the multiple reaction monitoring mode (MRM) for analysis. The absence of matrix effects was checked and the limits of detection for most toxins were low, ranging from 0.05 to 91.2 ng L⁻¹, depending on the compound. To validate the measurements, we performed recovery studies, falling in the range of 74–122%, with an intraday precision below 14.9% RSD. Full article

Savolitinib (Orpathys^®), was developed by (HUTCHMED (Shanghai, China) and, AstraZeneca (Gaithersburg, Maryland, USA), is an inhibitor of the c-Met receptor tyrosine kinase that is orally bioavailable. It was designed for the treatment of pillary and clear-cell renal-cell carcinoma (RCC), colorectal cancer, gastric cancer, and metastatic non-small-cell lung cancer (NSCLC). The current work aimed to develop a rapid, specific, green, and sensitive liquid chromatography tandem mass spectrometry (LC-MS/MS) methodology for estimating savolitinib (SVB) in human liver microsomes (HLMs) with application to an in vitro metabolic stability assessment of SVB in HLMs. The validation steps of the current LC-MS/MS methodology in the HLMs were carried out following US FDA bioanalytical method validation guidelines including sensitivity, selectivity, linearity, accuracy, stability, precision, extraction recovery, and matrix effect. SVB and olmutinib (OLM) were chromatographically separated on an Eclipse Plus C8 column using an isocratic mobile phase. SVB parent ions were generated using the positive mode of an electrospray ionization (ESI) source. SVB daughter ions were detected and quantified using the multiple reaction monitoring (MRM) mode of a triple quadrupole mass analyser. The constructed SVB calibration curve showed linearity over the range from 1 to 3000 ng/mL. The interday and intraday accuracy and precision of the developed LC-MS/MS analytical methodology were −6.67%–4.11% and −0.51%–8.75%, respectively. A lower limit of quantification (LLOQ) of 0.87 ng/mL confirmed the sensitivity of the established method. Furthermore, the eco-scale methodology using the in silico AGREE software was used for the greenness assessment of the current LC-MS/MS method, and the outcomes showed that the established method was very eco-friendly. The intrinsic clearance (Cl_int) and in vitro half-life (t_1/2) of SVB were 33.05 mL/min/kg and 24.54 min, respectively. SVB exhibited a moderate extraction ratio. The current study is the first to establish and validate LC-MS/MS for estimating SVB and assessing the metabolic stability of SVB. Full article

The rhizome of Atractylodes lancea (Thunb.) DC. (AL), called Maocangzhu in Chinese, is a geoherbalism medical herb in Jiangsu Province that is often used in the prescription of traditional Chinese medicine (TCM), such as for the treatment of COVID-19. The landform and climatic environment of each province varies greatly from south to north, which has an important influence on the chemical constituents in AL. However, there is a lack of research on the significance of its geoherbalism, especially in water-soluble parts other than volatile oil. In this study, eight known compounds were isolated and obtained as reference substances from AL. In addition, liquid chromatography coupled with triple-quadrupole time-of-flight tandem mass spectrometry (LC-triple TOF-MS/MS) and gas chromatography–mass spectrometry (GC-MS) were used to analyze and characterize chemical constituents from different habitats. Moreover, orthogonal partial least-squares discriminant analysis (OPLS-DA) was applied to reveal the differential metabolomics in AL from different habitats based on the qualitative information of the chemical constituents. Results showed that a total of 33 constituents from GC-MS and 106 constituents from LC-triple TOF-MS/MS were identified or inferred, including terpenoids, polyacetylenes, and others; meanwhile, the fragmentation pathways of different types of compounds were preliminarily deduced from the fragmentation behavior of the major constituents. According to the variable importance in projection (VIP) and p-values, only one volatile differential metabolite was identified by GC-MS screening: β-eudesmol. Overall, five differential metabolites were identified by LC-triple TOF-MS/MS screening: sucrose, 4(15),11-eudesmadiene; atractylenolide I, 3,5,11-tridecatriene-7,9-diyne-1,2-diacetate, and (3Z,5E,11E)-tridecatriene-7,9-diynyl-1-O-(E)-ferulate. This study provides metabolomic information for the establishment of a comprehensive quality evaluation system for AL. Full article

Fish are exposed to xenobiotics in the water. Uptake occurs mainly through the gills, which function as an exchange point with the environment. The gills’ ability to detoxify harmful compounds by biotransformation is an essential protection mechanism. The enormous numbers of waterborne xenobiotics requiring ecotoxicological assessment makes it necessary to replace in vivo fish studies with predictive in vitro models. Here, we have characterized the metabolic capacity of the ASG-10 gill epithelial cell line from Atlantic salmon. Inducible CYP1A expression was confirmed by enzymatic assays and immunoblotting. The activities of important cytochrome P450 (CYP) and uridine 5’-diphospho-glucuronosyltransferase (UGT) enzymes were established using specific substrates and metabolite analysis by liquid chromatography (LC) triple quadrupole mass spectrometry (TQMS). Metabolism of the fish anesthetic benzocaine (BZ) in ASG-10 confirmed esterase and acetyl transferase activities through the production of N-acetylbenzocaine (AcBZ), p-aminobenzoic acid (PABA) and p-acetaminobenzoic acid (AcPABA). Moreover, we were able to determine hydroxylamine benzocaine (BZOH), benzocaine glucuronide (BZGlcA) and hydroxylamine benzocaine glucuronide (BZ(O)GlcA) by LC high-resolution tandem mass spectrometry (HRMS/MS) fragment pattern analysis for the first time. Comparison to metabolite profiles in hepatic fractions, and in plasma of BZ-euthanized salmon, confirmed the suitability of the ASG-10 cell line for investigating biotransformation in gills. Full article

Studies of the neurobiological causes of anxiety disorders have suggested that the γ-aminobutyric acid (GABA) system increases synaptic concentrations and enhances the affinity of GABA_A (type A) receptors for benzodiazepine ligands. Flumazenil antagonizes the benzodiazepine-binding site of the GABA/benzodiazepine receptor (BZR) complex in the central nervous system (CNS). The investigation of flumazenil metabolites using liquid chromatography (LC)-tandem mass spectrometry will provide a complete understanding of the in vivo metabolism of flumazenil and accelerate radiopharmaceutical inspection and registration. The main goal of this study was to investigate the use of reversed-phase high performance liquid chromatography (PR-HPLC), coupled with electrospray ionization triple-quadrupole tandem mass spectrometry (ESI-QqQ MS), to identify flumazenil and its metabolites in the hepatic matrix. Carrier-free nucleophilic fluorination with an automatic synthesizer for [¹⁸F]flumazenil, combined with nano-positron emission tomography (NanoPET)/computed tomography (CT) imaging, was used to predict the biodistribution in normal rats. The study showed that 50% of the flumazenil was biotransformed by the rat liver homogenate in 60 min, whereas one metabolite (M1) was a methyl transesterification product of flumazenil. In the rat liver microsomal system, two metabolites were identified (M2 and M3), as their carboxylic acid and hydroxylated ethyl ester forms between 10 and 120 min, respectively. A total of 10–30 min post-injection of [¹⁸F]flumazenil showed an immediate decreased in the distribution ratio observed in the plasma. Nevertheless, a higher ratio of the complete [¹⁸F]flumazenil compound could be used for subsequent animal studies. [¹⁸F] According to in vivo nanoPET/CT imaging and ex vivo biodistribution assays, flumazenil also showed significant effects on GABA_A receptor availability in the amygdala, prefrontal cortex, cortex, and hippocampus in the rat brain, indicating the formation of metabolites. We reported the completion of the biotransformation of flumazenil by the hepatic system, as well as [¹⁸F]flumazenil’s potential as an ideal ligand and PET agent for the determination of the GABA_A/BZR complex for multiplex neurological syndromes at the clinical stage. Full article

Meropenem (MRP)-Vaborbactam (VBR) is a novel beta-lactam/beta-lactamase inhibitor used for the management of difficult-to-treat Gram-negative infections. Among critically ill patients, MRP-VBR shows remarkable inter-individual variability in pharmacokinetic behavior, thus justifying the implementation of therapeutic drug monitoring (TDM) for improving real-time management in different challenging scenarios. In this study, we developed and validated a fast and sensitive Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS) method for the simultaneous quantification of MRP and VBR in human plasma microsamples of 3 microliters. The analysis required only a single-step sample preparation and was performed by means of a fast chromatographic run of 4 min, followed by positive electrospray ionization and detection on a high-sensitivity triple quadrupole tandem mass spectrometer operated in multiple reaction monitoring modes. The straightforward analytical procedure was successfully validated, based on the EMA guidelines, in terms of specificity, sensitivity, linearity, precision, accuracy, matrix effect, extraction recovery, the limit of quantification, and stability. The novel method was successfully applied for simultaneously measuring MRP and VBR concentrations in more than 42 plasma samples collected from critically ill patients affected by carbapenem-resistant Gram-negative bacteria infections. Full article

A method was developed for the determination of matrine residues in quinoa (Chenopodium quinoa Willd.) plants and soil by liquid chromatography triple quadrupole tandem mass spectrometry (LC-MS/MS) with QuEChERS clean-up. Matrine from soil, quinoa roots, stems, leaves and seeds was extracted with 25% ammonia, 20 mL acetonitrile/methanol, salted with sodium chloride (NaCl) and purified with anhydrous magnesium sulfate (MgSO₄), N-propyl ethylenediamine (PSA) and graphitized carbon black (GCB). Then a chromatographic separation was performed on a Shim-pack XR-ODS II (75 mm × 2.0 mm, i. d., 2.2 µm) column with a gradient elution of 5 mmol/L ammonium formate-methanol as the mobile phase and monitored in multiple reaction monitoring modes (MRM) in electrospray positive ionization mode. The results showed that in the range of 0.005~1 mg/L, the linear correlation coefficients of matrine in the five matrices were all above 0.999. The LOQs for soil, quinoa roots, stems, leaves and seeds were 0.005, 0.005, 0.01, 0.01 and 0.005 mg/kg, respectively. The mean recoveries ranged from 74.42% to 98.37%, with RSDs of 1.25–6.84% at the three concentration addition levels. The average intra-day and inter-day recoveries were 73.92–92.36% and 78.56–90.18%, respectively, with RSDs below 8.72% and 9.43%. The recoveries and reproducibility of the method were superior. The method was used to determine the actual samples, which indicated that the half-lives of matrine in quinoa seeds, leaves, stems and soil were 1.28–1.32, 1.03–1.21, 0.81–0.92 and 0.93–0.97 d. It has a half-life below 30 d, which is an easily dissipated pesticide. The method is simple, sensitive, accurate, reliable and applicable to a wide range of applications, and it can achieve the rapid multi-residue determination of matrine to a certain extent. Next Generation Sequencing was used to explore the effects of exposure to high and low doses of matrine on soil bacterial communities and the composition of the three soils in the Qinghai Province (Haixi, Haidong and Haibei). The results showed that the number of ASVs increased significantly after treatment with matrine at an effective dose of 0.1 mg/kg than after treatment with matrine at an effective dose of 5.0 mg/kg. Similarly, bacterial abundance was higher after 0.1 mg/kg of matrine treatment than after 5.0 mg/kg of matrine treatment. The inhibitory effect on some bacterial flora was enhanced with an increase in matrine application, while the inhibitory effect on bacterial flora was weakened with time. Applying a certain dose of matrine e changed the relative abundance of the dominant bacterial genera of the soil bacteria. Full article

Selpercatinib (SLP; brand name Retevmo^®) is a selective and potent RE arranged during transfection (RET) inhibitor. On 21 September 2022, the FDA granted regular approval to SLP (Retevmo, Eli Lilly, and Company). It is considered the only and first RET inhibitor for adults with metastatic or locally advanced solid tumors with RET gene fusion. In the current experiment, a highly specific, sensitive, and fast liquid chromatography tandem mass spectrometry (LC-MS/MS) method for quantifying SLP in human liver microsomes (HLMs) was developed and applied to the metabolic stability evaluation of SLP. The LC-MS/MS method was validated following the bioanalytical methodology validation guidelines outlined by the FDA (linearity, selectivity, matrix effect, accuracy, precision, carryover, and extraction recovery). SLP was detected by a triple quadrupole detector (TQD) using a positive ESI source and multiple reaction monitoring (MRM) mode for mass spectrometric analysis and estimation of analytes ions. The IS-normalized matrix effect and extraction recovery were acceptable according to the FDA guidelines for the bioanalysis of SLP. The SLP calibration standards were linear from 1 to 3000 ng/mL HLMs matrix, with a regression equation (y = 1.7298x + 3.62941) and coefficient of variation (r² = 0.9949). The intra-batch and inter-batch precision and accuracy of the developed LC-MS/MS method were −6.56–5.22% and 5.08–3.15%, respectively. SLP and filgotinib (FLG) (internal standard; IS) were chromatographically separated using a Luna 3 µm PFP (2) stationary phase (150 × 4.6 mm) with an isocratic mobile phase at 23 ± 1 °C. The limit of quantification (LOQ) was 0.78 ng/mL, revealing the LC-MS/MS method sensitivity. The intrinsic clearance and in vitro t_1/2 (metabolic stability) of SLP in the HLMs matrix were 34 mL/min/kg and 23.82 min, respectively, which proposed an intermediate metabolic clearance rate of SLP, confirming the great value of this type of kinetic experiment for more accurate metabolic stability predictions. The literature review approved that the established LC-MS/MS method is the first developed and reported method for quantifying SLP metabolic stability. Full article