Simultaneous determination of the residues of anesthetics and sedatives in fish using LC-QLIT-MS/MS combined with DSPE.

Liquid chromatography coupled with quadrupole linear ion trap tandem mass spectrometry (LC-QLIT-MS/MS) technology operated in electrospray ionization (ESI) was developed for tracing anesthetic (AETs) and sedatives (SDTs) in fish. Sampling procedure was achieved by using acetonitrile extraction followed by dispersive solid phase extraction (DSPE) clean-up. Under the optimized laboratory conditions, reliable qualitative confirmation was obtained through the multiple reaction monitoring-information dependent acquisition-enhanced product ion (MRM-IDA-EPI) mode. Results indicated a favorable linear in the concentration range of 1-100 µg∙kg-1 (0.1-10 µg∙kg-1 for MS-222), with regression coefficient not less than 0.9997. The detection limit ranges from 0.03 to 0.4 µg∙kg-1 (S/N = 3). The validated method was applied to determine AETs and SDTs in fish with satidfied recoveries of 86.3 %-111.7 % and the relative standard deviations (RSD) of 1.9 %-8.9 % (n = 6). Practical samples analysis indicated that the proposed method is simple, rapid, sensitive and accurate for identification of AETs and SDTs.

Rapid Simultaneous Determination of Three Synthetic Cannabinoids in Urine and Plasma of Rats Using Ultra-High Performance Liquid Chromatography Tandem Mass Spectrometry.

Synthetic cannabinoids, a class of psychoactive compounds, are controlled as new psychoactive substances (NPSs) identified by the early warning system (EWS) of the European Monitoring Centre for Drugs and Drug Addiction (EMCDDA). At present, several new synthetic cannabinoids have appeared in the illegal drug market, including 4-methylnaphthalen-1-yl-(1-pentylindol-3-yl) methanone (JWH-122), methyl (1-(5-fluoropentyl)-1H-indazole-3-carbonyl)-L-valinate (5F-AMB), and methyl 2-(1-(4-fluorobenzyl)-1Hindazole-3-carboxamido)-3-methylbutanoate (AMB-FUBINACA). A convenient, rapid, and highly sensitive analytical method was developed to determine three synthetic cannabinoids in rat plasma and urine. The liquid chromatography tandem mass spectrometry (LC-MS/MS) method was optimized and validated to analyze the three synthetic cannabinoids in rat plasma and urine. The method identified intra-assay precision (1.3-9.0% and 2.8-6.7%), inter-assay precision (3.0-8.6% and 3.9-8.8%), limits of detection (0.003-0.004 ng/mL and 0.00125-0.002 ng/mL) and quantification (0.012-0.016 ng/mL and 0.003-0.005 ng/mL), recovery (95.4-106.8% and 92.0-106.8%) for rat plasma and urine, and the matrix effect (93.4-118.0%) for rat urine, and the correlation coefficients were above 0.99 in the linear range. The established LC-MS/MS method was successfully used to simultaneously detect the JWH-122 and 5F-AMB in rat plasma and JWH-122, 5F-AMB, and AMB-FUBINACA in rat urine. The present study provides methodological support for internal exposure assessment of three synthetic cannabinoids and promotes the quantitative analysis and technical supervision of synthetic cannabinoids.

Simultaneous determination of 58 pesticides and relevant metabolites in eggs with a multi-functional filter by ultra-high performance liquid chromatography-tandem mass spectrometry.

A sensitive method for the simultaneous determination of 58 pesticides and relevant metabolites in eggs was developed using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) after clean-up with a multi-functional filter (MFF) based on quick, easy, cheap, effective, rugged, and safe method (QuEChERS). The egg sample was extracted with 5 ml water and 10 ml 1% acetic acid in acetonitrile and then salt out with sodium chloride. The extracted solution was filtered directly through an MFF containing 50 mg PSA, 50 mg C18, and 150 mg magnesium sulphate before UHPLC-MS/MS analysis. The clean-up and filter procedures were integrated using the MFF to substantially improve the work efficiency. Good linearity was shown for each analyte, and all the correlation coefficients exceeded 0.99. The recoveries in the eggs at the five spiked levels were 74.4%-115.2%, and the relative standard deviations (RSDs) were less than 15.3%. The limit of detection (LOD) and the limit of quantitation (LOQ) of 58 pesticides and 8 metabolites in eggs were 0.1-1.0 µg/kg and 0.2-5.0 µg/kg, respectively. The decision limit (CCα) and detection capacity (CCß) were 3.4-111.1 µg/kg and 6.8-122.1 µg/kg, respectively. This method has also been successfully applied in the determination of actual eggs samples. This developed method is more effective and faster in the monitoring of pesticide residue in eggs compared to the traditional analytical method.

Safety investigation of Pulsatilla chinensis saponins from chronic metabonomic study of serum biomedical changes in oral treated rat.

ETHNOPHARMACOLOGICAL RELEVANCE: Pulsatilla chinensis (Bunge) Regel is a valuable traditional Chinese medicine (TCM) which is widely used for the treatment of schistosomiasis, inflammatory, bacterial infections. In recent years, P chinensis has been reported to exhibit antitumor activities. However, the mechanisms underlying its toxic effects remain largely unresolved. This paper is designed to investigate the damage of long-term oral P. chinensis saponins (PRS) and to explore its potential damage mechanisms by serum metabonomics approach. MATERIALS AND METHODS: The serum samples from control and PRS treated rats were analyzed by ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS) in positive ionization mode and negative ionization mode. Liver function index of ALT, AST and ALP, blood biochemistry and biomarkers were examined to identify specific changes of injury. Acquired data were subjected to principal component analysis (PCA) for differentiating the control and PRS treated groups. Then, serum metabolic profiling was analyzed and pathway analysis performed on the biomarkers reversed after PRS treated and further integration of metabolic networks. RESULTS: The results suggested that serum liver function indexes of ALT had significantly changed and stage increased. AST, ALP detection content show volatility changes. Changes in the 15 biomarkers found in the serum, such as acetaminophen glucuronide, 9 E, 11 E-linoleic acid, chenodeoxycholic acid, monoacylglycerides, sphingomyelin (SM), 7-ketodeoxycholic acid and 12-keto-deoxycholic acid, which were closely related to changes in liver injury. It could be seen clearly that with the change of the dosing time, the biomarkers in the serum have undergone obvious, regular and progressive changes through the score plot and corresponding loading plot. The underlying regulations of PRS-perturbed metabolic pathways were discussed according to the identified metabolites. CONCLUSION: The present study proves the potential of UPLC-QTOF-MS based metabonomics in mapping metabolic response. Long-term oral administration of P. chinensis saponins can cause chronic liver injury, and its safety needs further attention. It is of great significance in safeguarding human health to explore the damage mechanism of Pulsatilla chinensis saponins on liver by serum metabolomics.

Analysis of the Enantioselective Effects of PCB95 in Zebrafish (Danio rerio) Embryos through Targeted Metabolomics by UPLC-MS/MS.

As persistent organic pollutants, polychlorinated biphenyls (PCBs) accumulate in the bodies of animals and humans, resulting in toxic effects on the reproductive, immune, nervous, and endocrine systems. The biological and toxicological characteristics of enantiomers of chiral PCBs may differ, but these enantioselective effects of PCBs have not been fully characterized. In this study, we performed metabolomics analysis, using ultra-high performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) to investigate the enantioselective toxic effects of PCB95 in zebrafish (Danio rerio) embryos after exposure to three dose levels of 0.1, 1, and 10 µg/L for 72 h. Multivariate analysis directly reflected the metabolic perturbations caused by PCB95. The effects of (-)-PCB95 and (+)-PCB95 were more prominent than those of the racemate in zebrafish embryos. A total of 26 endogenous metabolites were selected as potential marker metabolites with variable importance at projection values larger than 1 and significant differences (p<0.05). These metabolites included amino acids, organic acids, nucleosides, betaine, and choline. The changes in these biomarkers were dependent on the enantiomer-specific structures of PCB95. Fifteen metabolic pathways were significantly affected, and several nervous and immune system-related metabolites were significantly validated after exposure. These metabolic changes indicated that the toxic effects of PCB95 may be associated with the interaction of PCB95 with the nervous and immune systems, thus resulting in disruption of energy metabolism and liver function.

Multi-residue determination of 210 drugs in pork by ultra-high-performance liquid chromatography-tandem mass spectrometry.

This paper presents a multi-residue analytical method for 210 drugs in pork using ultra-high-performance liquid chromatography-Q-Trap tandem mass spectrometry (UPLC-MS/MS) within 20min via positive ESI in scheduled multi-reaction monitoring (MRM) mode. The 210 drugs, belonging to 21 different chemical classes, included macrolides, sulfonamides, tetracyclines, ß-lactams, ß-agonists, aminoglycosides, antiviral drugs, glycosides, phenothiazine, protein anabolic hormones, non-steroidal anti-inflammatory drugs (NSAIDs), quinolones, antifungal drugs, corticosteroids, imidazoles, piperidines, piperazidines, insecticides, amides, alkaloids and others. A rapid and simple preparation method was applied to process the animal tissues, including solvent extraction with an acetonitrile/water mixture (80/20, v/v), defatting and clean-up processes. The recoveries ranged from 52% to 130% with relative standard deviations (RSDs)<20% for spiked concentrations of 10, 50 and 250µg/kg. More than 90% of the analytes achieved low limits of quantification (LOQs)<10µg/kg. The decision limit (CCα), detection capability (CCß) values were in the range of 2-502µg/kg and 4-505µg/kg, respectively. This method is significant for food safety monitoring and controlling veterinary drug use.

Simultaneous determination of 14 antiviral drugs and relevant metabolites in chicken muscle by UPLC-MS/MS after QuEChERS preparation.

A fast method for the simultaneous determination of 14 antiviral drugs and relevant metabolites in chicken muscle by ultra-high liquid chromatography tandem mass spectrometry (UPLC-MS/MS) was developed. The analytes included anti-influenza drugs (amantadine, rimantadine, oseltamivir, oseltamivir carboxylate, memantine, arbidol, and moroxydine), anti-herpes drugs (acyclovir, ganciclovir, famciclovir, penciclovir, ribavirin and its main metabolite TCONH2), and an immunomodulator (imiquimod). The samples were pretreated using a modified QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) method. The determination of the target compounds was conducted in less than 11.0min, and specificity was ensured by the use of multiple reaction monitoring (MRM) acquisition mode. Good linearities (R(2)>0.9928) were obtained in the range of 0.1-100µg/L, and the recovery rates were 56.2-113.4% with RSDs of 1.7-10.3% for intra-day precision and 2.4-8.8% for inter-day precision. The LODs and LOQs of all analytes were in the ranges of 0.02-1.0 and 0.05-2.5µg/kg, respectively. An analysis of real samples suggested that this method is simple, sensitive, reliable and practical for the detection of antiviral drugs in animal tissue.

Enantio-alteration of gene transcription associated with bioconcentration in adult zebrafish (Danio rerio) exposed to chiral PCB149.

Enantioselective enrichment of chiral PCB149 (2,2',3,4',5',6-hexachlorobiphenyl) was analysed in adult zebrafish (Danio rerio) exposed to the racemate, (-)-PCB149, and (+)-PCB149. Greater enrichment of (-)-PCB149 compared to (+) PCB149 was observed following 0.5 ng/L exposure; however, as the exposure time and concentration increased, racemic enrichment was observed in adult fish exposed to the racemate. No biotransformation between the two isomers was observed in fish exposed to single enantiomers. When zebrafish were exposed to different forms of chiral PCB149, enantioselective expression of genes associated with polychlorinated biphenyls (PCBs) was observed in brain and liver tissues and enantioselective correlations between bioconcentration and target gene expression levels were observed in brain and liver tissues. The strong positive correlations between expression levels of target genes (alox5a and alox12) and PCB149 bioconcentration suggest that prolonged exposure to the racemate of chiral PCB149 may result in inflammation-associated diseases. Prolonged exposure to (-)-PCB149 may also affect metabolic pathways such as dehydrogenation and methylation in the brain tissues of adult zebrafish. Hepatic expression levels of genes related to the antioxidant system were significantly negatively correlated with bioconcentration following exposure to (+)-PCB149.