Search Results (155)

An analytical method was established for the rapid determination of 45 pigments and preservatives in edible ink by ultra-high performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UHPLC-MS/MS), which provides technical support for the composition analysis and industrial development of edible ink. The samples were easily extracted with 75% aqueous methanol solution and purified with a Captiva EMR-Lipid HF solid-phase extraction cartridge. After filtration through a polytetrafluoroethylene (PTFE) membrane, the analytes were determined by UHPLC-MS/MS under multiple reaction monitoring (MRM) mode in both positive and negative ion modes. Poroshell 120 AQ-C18 was selected as the analytical column, and valve switching timing control was adopted during the gradient elution process. The external standard method was used for quantitative analysis. In the established method, the 45 pigments and preservatives exhibited good linear relationships within the mass concentration range of 0.0002–200.0 μg/mL. The limits of detection (LOD) and limits of quantification (LOQ) were 0.0004–8.00 mg/kg and 0.001–20.00 mg/kg, respectively. Using 25% aqueous glycerol solution as the blank matrix, the recoveries of analytes at different spiked levels met the detection requirements. The established method is simple and rapid, and can be applied to the qualitative and quantitative detection of typical pigments and preservatives in edible ink. Full article

Cellulose is the strongest cell wall polymer defining plant cell shape and growth, and the most abundant biopolymer on the Earth. Its synthesis by the plasma membrane (PM)-localized cellulose synthase complexes (CSCs) depends on surrounding lipids that establish the membrane microenvironment in which CSCs work and form vesicles delivering and removing CSCs to and from the PM by exo- and endocytosis. The role of exact lipid molecular species in these processes is poorly understood. In the present work we used hypocotyls of etiolated wild-type Col-0 and mutant ixr1-1 Arabidopsis thaliana seedlings grown with or without isoxaben, a specific cellulose synthesis inhibitor, as a model to reveal lipid molecular species associated with cellulose biosynthesis. Different lipid classes were separated by thin-layer chromatography (TLC) and their molecular species were analyzed by liquid chromatography–triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS). A total of 250 lipid molecular species were identified. Col-0 plants maintained stable levels of membrane glycerophospholipids but displayed significant remodeling of their acyl chains. In the presence of isoxaben, they accumulated three times more phosphatidic acids, a hallmark of a stress response. The isoxaben-resistant mutant ixr1-1 was characterized by a higher relative content of phosphatidylethanolamines, potentially rendering membranes more labile, as well as plastid galactolipids, which accumulated under isoxaben treatment. The multifaceted effects of isoxaben, including its impact on endomembrane lipids, suggest that it has additional binding sites beyond CSC. Full article

Following the passage of the Agriculture Improvement Act of 2018, demand for accurate cannabinoid quantification in hemp flowers has increased to ensure regulatory compliance. Liquid chromatography–tandem mass spectrometry (LC–MS/MS) using a triple-quadrupole mass spectrometer provides high sensitivity and selectivity and is well suited for this purpose; however, a review of the literature indicates that many published LC–MS/MS methods target only a limited number of cannabinoids, and reliable differentiation of structural isomers remains challenging. In this study, an LC–MS/MS method was developed for the simultaneous quantification of eighteen cannabinoids in hemp flowers. Baseline chromatographic separation of structural isomers enabled reliable differentiation of compounds with highly similar fragmentation patterns and allowed the use of the most sensitive multiple reaction monitoring (MRM) transitions for quantification. Both positive and negative ionization modes were employed to achieve optimal sensitivity using dynamic polarity switching within a single analytical run. Following validation in accordance with ISO/IEC 17025, the method was applied to a proficiency test hemp sample and six commercial hemp samples, demonstrating excellent time efficiency (11 min for 18 cannabinoids) and an exceptionally wide calibration range (8–5000 ng/mL, corresponding to 0.032–20% (w/w) for all cannabinoids). Full article

This study investigated the anti-inflammatory material basis and quality control of Pinellia ternata (P. ternata) to provide a modern scientific interpretation for its therapeutic properties. First, ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry (UHPLC-Q-TOF-MS/MS) analysis was used to analyze different polar fractions of P. ternata, resulting in the identification of 79 compounds. Next, an in vitro evaluation using an LPS-induced RAW264.7 cell inflammation model revealed that the ethyl acetate fraction exhibited the most significant inhibition of nitric oxide (NO) production. Three cyclodipeptides, cyclo (Pro-Leu), cyclo (Phe-Pro), and cyclo (Leu-Phe), which displayed notable differences from other fractions, were subsequently screened. Molecular docking studies showed binding free energies below −5 kcal/mol with inducible nitric oxide synthase (iNOS), indicating potential anti-inflammatory targeting properties. Cellular experiments further confirmed that the reduction in NO production induced by these cyclodipeptides ranged from 11.03% to 40.38%. To enable their simultaneous quantification, a method based on ultra-high-performance liquid chromatography–triple quadrupole tandem mass spectrometry (UHPLC-QQQ-MS/MS) in the multiple reaction monitoring (MRM) mode was established, meeting all analytical validation criteria. Application of this method to P. ternata samples from different origins and growth conditions demonstrated that the contents of these cyclodipeptides were significantly influenced by both the origin and cultivation method. In conclusion, this study preliminarily identifies cyclodipeptides as an important anti-inflammatory material basis of P. ternata, and the established quantitative method provides methodological support and data for constructing its quality evaluation system. Full article

To analyze the phytogenic components of honey of Amorpha fruticosa L. (AFH) and establish a targeted quantitative method, the liquid chromatography-mass spectrometry (LC-MS) based metabolomic technology was used in this study. Firstly, high performance liquid chromatography—quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS) untargeted metabolomics technology was used to screen candidate markers by comparing AFH metabolites with plant chemicals of Amorpha fruticosa L. Afterward, high performance liquid chromatography—triple quadrupole tandem mass spectrometry (HPLC-QQQ-MS/MS) was used to verify and identify the candidate markers, confirming ononin as the characteristic phytogenic marker of AFH, and determining its content range in AFH as 76.84–93.27 μg/kg (absent in acacia, rape, jujube, and Galla chinensis honey). Then, network pharmacology and molecular docking techniques were adopted to explore the gastric protective mechanism of ononin, and the results showed that ononin strongly binds AKT1 (binding free energy −8.0677 kcal/mol). Using the established method, the LC-MS analytical method for ononin in honey established in this study may be used for the authenticity identification of the characteristic phytogenic markers of AFH. Full article

Phenolic molecules represent one of the most prevalent and biologically important categories of secondary metabolites. Within this diverse group, phenolic acids and flavonoids are the most extensively studied categories, primarily due to their structural diversity and broad spectrum of reported bioactivities. We first provide an overview of the physicochemical characteristics of flavonoids and phenolic acids and discuss how these properties relate to mass spectrometry (MS) fragmentation patterns and chromatographic behavior, including retention characteristics and isomer resolution. Next, we systematically examine the utilization of MS-based procedures for the characterization of flavonoids and phenolic acids in complex natural matrices. We initially examine targeted liquid chromatography–tandem mass spectrometry (LC–MS/MS) utilizing triple-quadrupole (QQQ) platforms, focusing on selected/multiple reaction monitoring (SRM/MRM) and associated scanning techniques (product-ion and precursor-ion scans). We summarize validated methodologies and strategies for both absolute and relative quantification, including stable-isotope dilution, matrix-matched calibration or standard addition, and internal-standard normalization. We subsequently analyze untargeted high-resolution mass spectrometry methodologies (direct injection and coupled to liquid chromatography), highlighting recent progress in data acquisition while addressing ongoing challenges in computational processing. Finally, we present a brief evaluation of commonly used extraction and clean-up processes, highlighting their practical impact on phenolic recoveries. Full article

Introduction: Currently, there are few tools for monitoring recovery in substance use disorder. As substance use has increased in prevalence, tools for measuring recovery are needed to improve therapeutic outcomes. Measuring the kynurenine pathway for imbalances in metabolites could be a possible solution to monitor recovery. Methods: We developed a liquid chromatography–tandem mass spectrometry (LC-MS/MS) method to quantify tryptophan, kynurenine, kynurenic acid, and quinolinic acid in urine. Metabolites were separated using a stepwise gradient and detected with an Agilent 6460 triple quadrupole mass analyzer. The samples were extracted using a simple protein precipitation protocol. Method validation was performed using routine toxicology urine samples and laboratory contrived samples. The performance characteristics assessed included precision, linearity, stability, interference, and matrix effects. Additionally, urine samples from two cohorts (illicit drug-negative and drug-positive; n = 120 per cohort) were analyzed for significant concentration differences in the four metabolites using Mann–Whitney, PCA, and Area Under the Receiver Operating Characteristic Curve statistical analysis. Results: The LC-MS/MS assay was linear from 195 to 100,000 ng/mL for tryptophan, 6 to 3000 ng/mL for kynurenine, 14 to 7200 ng/mL for kynurenic acid, and 125 to 64,000 ng/mL for quinolinic acid using an 8-point calibration curve. Imprecision ranged from 1.17% to 12.46% CV using two controls that spanned the analytical measurement range. Matrix effects were observed; however, the use of labeled internal standards matching the metabolites of interest minimized the impact on quantification. The extraction recovery efficiency was acceptable for the analytical validation. Ambient stability extended to 10 days, resulting in individual sample biases of up to 22%. A statistically significant increase in TRP, KYN, and QA was observed in drug-positive urine compared to illicit drug-negative urine (p < 0.01). Conclusion: We developed a rapid and sensitive LC-MS/MS method for quantifying tryptophan, kynurenine, kynurenic acid, and quinolinic acid in urine that can aid in future research elucidating the relationship between substance use disorders and tryptophan metabolism. Full article

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants that tend to accumulate in solid matrices such as sewage sludge, raising concerns regarding their fate and potential ecological risks. This study aimed to develop and validate a robust analytical method for the accurate determination of PFAS in dehydrated sludge. A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was optimized for 28 PFAS, including perfluoroalkyl carboxylic acids (PFCAs) and sulfonic acids (PFSAs). Solid–liquid extraction with basic methanol was followed by cleanup using a cartridge packed with ferrite and sodium sulfate to remove moisture and particulate interferences. Chromatographic separation was performed with an Avantor^® ACE^® PFAS Delay column coupled to an Agilent triple quadrupole MS operating in negative electrospray ionization mode. The method achieved excellent sensitivity (MDL < 0.02 µg/g dry weight for most compounds), satisfactory precision (RSD < 15%), and recoveries between 80–118%. Optimization of mobile phase additives, gradient conditions, and MS parameters enhanced chromatographic resolution and signal-to-noise ratio. The validated method demonstrates high reliability for PFAS determination in complex solid matrices and can be applied as a valuable tool for environmental monitoring and risk assessment of sludge management practices. Full article

Background/Objectives: Phosphatidylinositol (PI) species are bioactive lipids implicated in liver fibrogenesis. Hepatitis C virus (HCV) relies on host lipid metabolism for infection. The relationship between serum PI profiles, chronic HCV, and liver injury remains incompletely defined. Methods: Fourteen PI species were quantified by direct flow injection–tandem mass spectrometry (FIA–MS/MS; triple quadrupole) in serum from 178 patients with chronic HCV at three time points: before treatment and at weeks 4 and 12 after starting direct-acting antiviral (DAA) therapy. Results: At baseline, PI 34:1, 36:1, and 36:3 were higher in patients with ultrasound-diagnosed cirrhosis than in those without, whereas PI 38:4, 40:5, and 40:6 were lower. In non-cirrhotic patients, PI 36:3, 36:4, 38:3, 38:4, and 38:5 increased, while PI 40:5 and 40:6 declined at weeks 4 and 12 after therapy start. In cirrhosis, viral cure was not associated with changes in PI species. By the end of therapy, cirrhotic patients showed higher PI 36:3 and lower PI 38:4 than non-cirrhotic patients. Genotype 3a was associated with lower PI 38:3, 38:4, and 38:5; the reduction in PI 38:4 persisted to the end of therapy. Across time points, most PI species did not correlate with routine markers of liver injury or inflammation. Conclusions: HCV cure remodels the serum PI profile in non-cirrhotic patients. These findings suggest that altered PI profiles are primarily linked to HCV infection, supporting a role for PI lipids in viral propagation. Full article

Aristolochic acid I (AAI) is widely recognized as a genotoxic and cytotoxic compound. To rationally propose detoxification strategies, it is essential to fully elucidate the in vivo disposition of AAI. Nevertheless, the toxicokinetic characteristics of AAI, particularly the possible involvement of the recirculation process, remain incompletely understood. In this research, toxicokinetics of AAI was studied following a single oral administration of AAI in Fisher rats (10, 30 and 100 mg/kg, n = 6). A method of ultra-performance liquid chromatography coupled with triple quadrupole tandem mass spectrometry (UPLC-QQQ-MS/MS) was developed to achieve the quantitation of AAI in rat plasma. Plasma concentration–time profiles and kinetic parameters were analyzed to characterize the toxicokinetic behavior of AAI. A secondary elevation was observed in the plasma concentration–time profiles of AAI, suggesting the existence of AAI reabsorption. The non-linear elimination kinetics of AAI might be attributed to capacity-limited excretion via bile. Additionally, the biliary excretion of AAI and several key metabolites was also explored through qualitative analysis of bile samples. For the first time, AAI-O-glucuronide was identified in bile, providing further support for enterohepatic recirculation (EHR)-mediated reabsorption of AAI. In conclusion, these findings provided solid evidence for EHR-mediated reabsorption of AAI in rats. The recirculation process might be a key mechanism responsible for the prolonged retention of AAI. In the future, detoxification strategies targeting the EHR process could be effective approaches to minimize the systemic exposure of AAI. Full article

α-Cyperone (C₁₅H₂₂O), a critical bioactive sesquiterpene, serves as a representative chemical compound of Cyperi Rhizoma—a classical functional food. To investigate the pharmacokinetic characteristics of α-cyperone, a quantified method was developed in plasma, bile, urine, and feces by ultra-high-performance liquid chromatography tandem triple quadrupole mass spectrometry (UHPLC-QQQ-MS/MS). After being validated, the developed method was applied in a plasma pharmacokinetic study as well as biliary, urinary, and fecal excretion kinetics studies. It revealed poor absolute bioavailability (F = 1.36%) and rare excretion (total cumulative excretion = 0.022%) of α-cyperone, which suggested extensive first-pass metabolism. This study provided crucial insight into explaining the in vivo process and promoting the further development of α-cyperone. Full article

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

A high-throughput method for the determination of a variety of chemical hazards in poultry muscle and egg samples was established via ultra-performance liquid chromatography–tandem triple quadrupole mass spectrometry (UPLC–QqQ-MS). The sample preparation procedure was developed based on this quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and validated for 280 chemical hazards potentially present in poultry products. The target compounds in poultry samples were extracted with a 1% formic acid–acetonitrile solution (15:85, v/v), and the metal ions in the matrix were chelated by adding ethylenediaminetetraacetic acid disodium salt (Na₂EDTA). The supernatant was purified using Enhanced Matrix Removal (EMR) lipid sorbent. Chromatographic gradient separation was performed on an ACQUITY UPLC BEH C18 (2.1 mm × 100 mm, 1.7 μm) column with multiple reaction monitoring (MRM) under both negative- and positive-ion mode. Internal standard calibration or matrix-matched calibration was used for the quantitation. The results showed that good linearity was achieved for each target compound with correlation coefficients (R²) ≥ 0.99. The limits of detection (LODs) ranged from 0.05 to 10 µg/kg, and the acceptable limits of quantification (LOQs) were determined to be 0.1–20 µg/kg for all 280 compounds. Approximately 90% of the target compounds exhibited mean recoveries ranging from 60% to 120%, with relative standard deviations (RSDs) within 16.2%. This method can be used for the high-throughput rapid detection of prohibited drug residues in poultry eggs due to its easy operation and high accuracy. It was applied in real sample detection, and 43 chemicals including metronidazole were found in 211 poultry samples, with a concentration range of 0.11–638 μg/kg. Full article

Background: This study presents a sensitive method for the simultaneous determination of organic acids, flavonoids, and amino acids in Mume Fructus (MF) using ultra-performance liquid chromatography coupled with triple-quadrupole linear ion-trap tandem mass spectrometry (UPLC-QTRAP-MS/MS). Methods: Analysis was performed on a UPLC system (Shimadzu, Kyoto, Japan) equipped with a quaternary pump solvent management system, an online degasser, a triple-quadrupole mass detector, and an autosampler. An Agilent ZORBAX SB-C18 column (3.0 mm × 100 mm, 1.8 µm) was used for chromatographic analyses. The mobile phase was distributed between 0.2% aqueous formic acid (A) and 0.2% formic acid acetonitrile (B) at a velocity of 0.2 mL/min. The gradient evolution protocol was 0–2 min at 90–70% B; 3–7 min at 70–50% B; 7–10 min at 50–20% B; 10–14.5 min at 20–90% B; and 14.5–17 min at 10% B. Results: The method was validated for matrix effects, linearity, limits of detection/quantification, precision, repeatability, stability, and recovery of target components. It effectively determined all target compounds in 12 MF batches from different drying methods. Conclusions: Principal component analysis (PCA) of 47 active components was conducted to evaluate MF quality comprehensively. The proposed method serves as a reliable approach for assessing the consistency of MF’s quality and therapeutic efficacy. Full article

Anxiety and stress-related disorders affect all ages in all geographical areas. As high anxiety and chronic stress result in the modulation of mitochondrial pathways, intensive research is being carried out on pharmaceutical interventions that alleviate pertinent symptomatology. Therefore, innovative approaches being currently pursued include substances that target mitochondria bearing an antioxidant moiety. In this study, a newly synthesized antioxidant consisting of triphenylphosphine (TPP), a six-carbon alkyl spacer, and hydroxytyrosol (HT) was administered orally to mice via drinking water. Cerebellum and liver samples were collected and analyzed using ultra-high-performance liquid chromatography-tandem triple quadrupole mass spectrometry (UHPLC-MS/MS) to assess the levels of TPP-HT in the respective tissues to evaluate in vivo administration efficacy. Sample preparation included extraction with appropriate solvents and a preconcentration step to achieve the required sensitivity. Both methods were validated in terms of selectivity, linearity, accuracy, and limits of detection and quantification. Additionally, a workflow for evaluating and statistically summarizing multiple fortified calibration curves was devised. TPP-HT penetrates the blood–brain barrier (BBB), with a level of 11.5 ng g⁻¹ quantified in the cerebellum, whereas a level of 4.8 ng g⁻¹ was detected in the liver, highlighting the plausibility of orally administering TPP-HT to achieve mitochondrial targeting. Full article