Resolution Liquid Chromatography-tandem Mass Spectrometry Research Articles

Simultaneous quantitation of 17 female sex hormones in illegal products by validated LC-high resolution MS and LC-tandem MS methods.

The consumption of food and drugs adulterated with female sex hormones can have an extremely adverse effect on human health. Therefore, developing appropriate monitoring methods for the identification of various exogenous female sex hormones is crucial for minimizing and eliminating the related health risks. Herein, 17 female hormones categorized into two groups, estrogen and progestin, were analyzed using reversed phase LC coupled to Orbitrap or triple quadrupole MS. The fragmentation patterns for all compounds were discovered, and fragmented structures were also derived from them through LC-high resolution MS followed by qualitative sample analysis. In addition, quantitative analysis of 67 samples of illicit drugs and dietary supplements was performed using the validated LC-tandem MS method. Female hormone components were detected in two samples of an unauthorized injectable solution and a tablet-type drug. Medroxyprogesterone was detected in the samples in the range of 96.4-206 ng/g. Notably, eight components similar in structure to steroids were simultaneously detected as male sex hormones by confirming their fragmentation ion patterns using LC-high resolution MS. The developed methods thus offer a dependable, and practically applicable approach for the screening and detection of exogenous female sex hormones in real food and drug samples to ensure public health. This article is protected by copyright. All rights reserved.

Prevalence of the neurotoxin domoic acid in the aquatic environments of the Bohai and Northern Yellow seas in China

Domoic acid (DA), a natural marine phytotoxin produced by toxigenic algae, is harmful to fishery organisms and the health of seafood consumers. In this study, we performed a whole-sea area investigation of DA in seawater, suspended particulate matter (SPM), and phytoplankton of the Bohai and Northern Yellow seas to clarify the occurrence, phase partitioning, spatial distribution, potential sources, and environmental influencing factors of DA in the aquatic environment. DA in different environmental media was identified using liquid chromatography-high resolution mass spectrometry and liquid chromatography-tandem mass spectrometry. DA was found to be predominantly in a dissolved phase (99.84 %) in seawater with only 0.16 % in SPM. Dissolved DA (dDA) was widely detected in nearshore and offshore areas of the Bohai Sea, Northern Yellow Sea, and Laizhou Bay with concentrations ranging from < limits of detection (LOD) to 25.21 ng/L (mean: 7.74 ng/L), < LOD to 34.90 ng/L (mean: 16.91 ng/L), and 1.74 ng/L to 38.20 ng/L (mean: 21.28 ng/L), respectively. dDA levels were relatively lower in the northern part than in the southern part of the study area. In particular, the dDA levels in the nearshore areas of Laizhou Bay were significantly higher than in other sea areas. This may be due to seawater temperature and nutrient levels exerting a crucial impact on the distribution of DA-producing marine algae in Laizhou Bay during early spring. Pseudo-nitzschia pungens may be the main source of DA in the study areas. Overall, DA was prevalent in the Bohai and Northern Yellow seas, especially in the nearshore aquaculture zone. Routine monitoring of DA in the mariculture zones of the northern seas and bays of China should be performed to warn shellfish farmers and prevent contamination.

Changes in the frequency and pattern of drugs detected among suspected drug users during the COVID-19 pandemic in Turkey.

From March 13 until May 31, 2020, a complete lockdown in Turkey was planned and implemented by the government of Turkey. The vulnerable population with substance use disorders was affected more than others due to the social isolation measures meant to control the pandemic. This study presents detailed and broad data on drug abuse in suspected cases during the first wave of the COVID-19 pandemic in Turkey and compares the frequencies and patterns of drug abuse before and during the pandemic. The samples were screened by liquid chromatography-high resolution mass spectrometry and liquid chromatography-tandem mass spectrometry. Blood and urine samples of suspected users (n = 9669) were analyzed for drugs of abuse during the first wave of the COVID-19 pandemic and compared with their results (n = 8727) obtained just before the COVID-19 pandemic. The use of party drugs, such as MDMA and cocaine, and the classic illicit drug cannabis was significantly decreased and followed the same trend after complete lockdown was over. In contrast, methamphetamine use increased significantly during the lockdown period and continued after the lockdown. Interestingly, the number of tests that were positive for pregabalin as a misused licit drug increased, and this increase continued after the lockdown. The results showed a significant increase in drug abuse cases and changes in drug abuse trends, with an alteration toward more easily obtainable and lower-priced drugs. Using more dangerous and easily available licit and illicit drugs may cause serious health problems.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00414-022-02794-1.

Assessment of carbonic anhydrase 3 as a marker for meat authenticity and performance of LC-MS/MS for pork content

In recent years, food fraud is a global issue that has raised wide public concern. Mass spectrometry techniques have a significant advantage of qualitatively and quantitatively analyzing food authenticity, especially for highly processed meat products. In this work, a simple and specific, rapid resolution liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed and validated for the determination of pork content in processed meat products according to internal standard (ISTD) method. To improve the efficiency of sample preparation, simplified bead-beating and enzymolysis process were investigated. In contrast with different heat-stable and specific porcine-peptides, EPITVSSDQMAK, GGPLTAAYR, HDPSLLPWTASYDPGSAK from Carbonic anhydrase 3 proved to have an excellent quantitative ability, thus obtaining good linear relationship and satisfactory recovery. This method was successfully applied to different types of meat products, thus demonstrating that complex mixtures of pork content can be accurately quantified.

An integrative proteogenomics approach reveals peptides encoded by annotated lincRNA in the mouse kidney inner medulla.

Long noncoding RNAs (lncRNAs) are intracellular transcripts longer than 200 nucleotides and lack protein-coding information. A subclass of lncRNA known as long intergenic noncoding RNAs (lincRNAs) are transcribed from genomic regions that share no overlap with annotated protein-coding genes. Increasing evidence has shown that some annotated lincRNA transcripts do in fact contain open reading frames (ORFs) encoding functional short peptides in the cell. Few robust methods for lincRNA-encoded peptide identification have been reported, and the tissue-specific expression of these peptides has been largely unexplored. Here we propose an integrative workflow for lincRNA-encoded peptide discovery and test it on the mouse kidney inner medulla (IM). In brief, low molecular weight protein fractions were enriched from homogenate of IMs and trypsinized into shorter peptides, which were sequenced by high resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS). To curate a hypothetical lincRNA-encoded peptide database for peptide-spectrum matching following LC-MS/MS, we performed RNA-Seq on IMs, computationally removed reads overlapping with annotated protein-coding genes, and remapped the remaining reads to a database of mouse noncoding transcripts to infer lincRNA expression. Expressed lincRNAs were searched for ORFs by an existing rule-based algorithm, and translated ORFs were used for peptide-spectrum matching. Peptides identified by LC-MS/MS were further evaluated by using several quality control criteria and bioinformatics methods. We discovered three novel lincRNA-encoded peptides, which are conserved in mouse, rat, and human. The workflow can be adapted for discovery of small protein-coding genes in any species or tissue where noncoding transcriptome information is available.

Cross-validation of biomonitoring methods for polycyclic aromatic hydrocarbon metabolites in human urine: Results from the formative phase of the Household Air Pollution Intervention Network (HAPIN) trial in India

The Household Air Pollution Intervention Network (HAPIN) trial is evaluating health benefits of a liquefied petroleum gas (LPG) stove intervention in biomass cook-fuel using homes (n = 3200) in four low-and middle-income countries (LMICs) that include Peru, Guatemala, Rwanda and India. Longitudinal urine samples (n = 6000) collected from enrolled pregnant women, infants and older women will be analyzed for biomarkers associated with exposure and health outcomes. We report results from cross-validation of a lower cost high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method with a higher resolution liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the measurement of 1-hydroxypyrene (1PYR) and 2-naphthol (2NAP). Twenty-five split urine samples were analyzed by HPLC-FLD method at the India trial site in Chennai, India and by LC-MSMS method at the trial wide Biomarker Coordinating Center, Emory University, USA. The limits of detection (LOD) for the HPLC-FLD method were 0.02 ng/mL and 0.07 ng/mL for 2NAP and 1PYR, respectively. Bland-Altman analysis estimated a bias of 2.98 ng/ml for 2NAP (95% CI: −5.22, −0.75) and 0.09 ng/mL for 1PYR (95% CI: −0.02, 0.21) with HPLC-FLD levels being lower than LC-MSMS levels at higher concentrations. Analyses of additional urine samples (n = 119) collected during the formative phase of the HAPIN trial in India, showed 2NAP and 1PYR levels to be consistently above the limit of quantification (LOQ) and demonstrated the applicability of the method. The HPLC-FLD method can serve as a cost-effective and reliable analytical method to measure 2NAP and 1PYR in human urine in LMICs, within and beyond the HAPIN trial.

MCS Hypershear Modulates Platelet Membrane Fluidity, Lipid Species, and is Gender Specific

Shear-mediated platelet activation (SMPA) is a main driver of MCS thrombosis. A target of MCS shear, driving activation, is the platelet membrane - leading to potential alteration of biophysical properties. Here, we examined the effect of shear stress-accumulation on platelet membrane fluidity and on platelet lipid species profile - both retained (membrane) and free (ejected) post-activation. Human gel-filtered platelets (20,000 plts/uL) were exposed to shear in a hemodynamic shearing device (70 dynes/cm2 x 10'); or to thrombin (1U/mL x 10') as a chemical agonist comparator. Membrane fluidity was determined by ໿fluorescence anisotropy of the probe TMA-DPH (1uM, 5' @ 37C). Platelet lipids - both retained (cellular) and free (ejected) following activation - were extracted and analyzed via high resolution liquid-chromatography tandem mass spectrometry (LC-MS/MS). Shear stress accumulation increases platelet membrane fluidity - with a 6% increase noted even for the brief shear exposure examined. Shear stress exposure results in significant alteration of overall platelet lipid composition, with increase in supernatant lipid species relative to the non-activated samples such that 72% of identified lipid species have >2-fold increase. Lipid species altered in the supernatant of sheared platelets were unaltered under thrombin treatment. Interestingly, within the limits of our analysis, a gender-based difference in retained lipid species was seen with shear but not with thrombin activation. Male donors showed at least a 2-fold decrease in 53% of lipids identified in the pellet of the sheared platelets using negative mode MS. In contrast, female donors had only 6% of lipids decrease >2-fold relative to non-activated platelets, while 77% of lipids showed a less than 2-fold change in either direction. Shear stress has a specific impact on platelet membranes - leading to an increase in fluidity, and alteration of platelet lipidomic profile, which differs from biochemical activation, with evident gender-based differences. Specifically, shear leads to an increase in the number of lipids ejected across all donors, and a male-preferred decrease in retained lipid species. This sex-based difference in platelet composition resulting from shear exposure raises the issue of altered responsiveness that may impart gender differences in in MCS outcomes.

Development of an LC-MS/MS method for quantitative analysis of Chlorogenic acid in human plasma and its application to a pharmacokinetic study in Chinese patients with advanced solid tumor

A simple and specific, rapid resolution liquid chromatography-tandem mass spectrometry (LC–MS/MS) method was developed and validated for determination of chlorogenic acid in human plasma using neochlorogenic acid as the internal standard. Plasma samples were precipitated with methanol and separated on a Zorbax C18 column (50 × 2.1 mm, i.d. 1.8 μm) at a flow rate of 0.4 mL/min using a gradient mobile phase of methanol-water containing 0.1% formic acid (v/v). The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring in negative ESI mode. The method was fully validated over the concentration range of 10–2000 ng/mL. The indicators of inter- and intra-day precision (RSD%) were all within 10.7%, and the accuracy (RE%) was ranged from -3.0% to 10.6%. Moreover, we evaluated this bioanalytical method by re-analysis of incurred samples as an additional measure of assay reproducibility. This method was successfully applied to pharmacokinetic study of CGA in Chinese subjects with advanced solid tumor after intramuscular injection administration of Chlorogenic acid for injection (CAFI).

Proteomic Identification of Novel Plasma Biomarkers and Pathobiologic Pathways in Alcoholic Acute Pancreatitis.

Acute pancreatitis (AP) is a painful and potentially life-threatening disorder with the potential for therapeutic interventions. Biomarkers that characterize cases by severity and pathogenic mechanisms involved are not yet available but needed for the implementation of rational therapies. Here, we used shotgun proteomics to obtain information from plasma samples about local and systemic pathologies taking place during cases of alcoholic AP. Plasma was obtained at Kaunas University of Medicine Hospital (Lithuania) from 12 AP patients of alcohol related etiology (median age of 40) within 24 h of presentation, and 12 age-matched, healthy controls. Patients entered into the study had moderately severe AP with the following characteristics: mean blood lactate dehydrogenase level of 1127 mg/dl; median APACHEII score of 5.5 and mean IMRIE score of 3.5. For proteomic analysis, less-abundant proteins in plasma samples were enriched using Top 12 abundant protein depletion columns. Further processing was performed by a modified filter-assisted sample preparation combined with tandem mass tag labeling for quantitation. Samples were analyzed using an Orbitrap Elite mass spectrometer for high resolution liquid chromatography–tandem mass spectrometry (LC–MS/MS). Our analysis revealed 31 proteins that exhibited significant 1.5-fold or higher increases in the AP compared to control patients, and six that were significantly decreased. Gene ontology analysis indicated a strong correlation with exosomal origin in the elevated proteins, with 29/31 (93.5%) associated with this extracellularly-secreted compartment. Elevated proteins included established and proposed biomarkers of AP including C-reactive protein, LPS-binding protein, intercellular adhesion molecule-1, and von Willebrand factor, as well as several novel potential biomarkers. These results provide the methodology for proteomic analysis of plasma samples to discover novel biomarkers that characterize pancreatitis cases by pathogenic mechanism as well as disease activity at an early stage that is highly informative for routine clinical practice and clinical trials.

Endocrine disruptors and neonatal anthropometry, NICHD Fetal Growth Studies - Singletons

BackgroundIntrauterine exposure to endocrine disrupting chemicals (EDCs) has been equivocally associated with birth weight, length and head circumference with limited attention to anthropometric endpoints such as umbilical circumference and limb lengths. ObjectiveTo explore 76 prenatal maternal plasma EDC concentrations in a healthy obstetric cohort and 7 neonatal anthropometric endpoints by maternal race/ethnicity. MethodsThe study cohort comprised 2106 (564 White, 549 Black, 590 Hispanic, 403 Asian) healthy pregnant women recruited from 12 U.S. clinical sites between 2009 and 2012 who were followed through delivery. Neonates underwent standardized anthropometric assessment (weight, length, head and umbilical circumference, and mid- upper arm and thigh length). Plasma EDC concentrations were quantified using high resolution gas chromatography-high resolution mass spectrometry and liquid chromatography-tandem mass spectrometry. EDCs were log-transformed and rescaled by their deviations (SD) when modeled relative to neonatal endpoints using linear regression adjusting for age, education, pre-pregnancy body mass index (BMI), serum cotinine, serum lipids for lipophilic chemicals, and a race/ethnicity interaction term; p-values had false discovery rate correction (<0.05). ResultsThe cohort comprised women aged 28 (SD = 5) years with normal BMIs (23.6 kg/m2, SD = 3). Maternal EDC concentrations varied by self-identified race/ethnicity and neonatal outcomes, though no specific EDC was consistently associated with neonatal anthropometric outcomes across racial/ethnic groups. For the overall cohort, perfluorooctanoic acid was negatively associated with birth length per SD increase in concentration (β = −0.23 cm; 95% CI −0.35, −0.10), while perfluorohexanesulfonic acid was negatively associated with umbilical circumference (β = −0.26 cm; 95% CI −0.40, −0.13), perfluorodecanoic acid with arm length (−0.09 cm; 95% CI −0.14, −0.04), and PCBs congeners 118/106 (−0.12 cm; 95% CI −0.20, −0.04) and 146/161 (−0.14 cm; 95% CI −0.23, −0.05) with thigh length, as were 7 other poly-and-perfluorinated alkyl substances (PFASs). ConclusionsAmong healthy pregnant women with low risk antenatal profiles and relatively low EDC concentrations, reductions in umbilical circumference and bone lengths may be a sensitive marker of intrauterine EDC exposure, particularly for PFAS.

Microdialysis combined with RRLC–MS/MS for the pharmacokinetics of two major alkaloids of Bi qi capsule and the potential roles of P-gp and BCRP on their penetration

Bi qi capsule (BQC) is a traditional Chinese medicine prescription that is clinically used for the treatment of rheumatoid arthritis. Strychnine and brucine, as two typical kinds of alkaloids, are the primary active and neurotoxic constituents of BQC. In this study, a sensitive and reliable rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) quantitative method was used to determine the concentrations of brucine and strychnine in rat brain and blood dialysates. The blood-brain barrier (BBB) penetration of free brucine and strychnine and their pharmacokinetic characteristics were investigated by the validated RRLC-MS/MS method coupled with in vivo microdialysis for the first time. The dialysate brain-blood AUC ratios of brucine were 0.098, 0.44 and 0.40 respectively at 0.4, 0.8 and 1.6 g kg−1 doses of BQC, and the dialysate brain-blood AUC ratios of strychnine were 0.20, 1.25 and 2.06 respectively at 0.4, 0.8 and 1.6 g kg−1 doses of BQC. The high brain-blood AUC ratios of brucine and strychnine were observed in medium and high dose groups of BQC. In addition, the effects of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) on brucine and strychnine across BBB were also studied using the above method as well as molecular docking. The results prompted that brucine was the substrate of P-gp, and strychnine might be the inhibitor of P-gp. Brucine and strychnine showed high brain penetration, so it is very important to well control the clinic dosage of BQC and manufactory quality for avoiding the side effects and obtaining good therapeutic efficacy. Our study could be further used in investigating BBB penetration for other drugs caused neurotoxicity.

Antibiotics in Crab Ponds of Lake Guchenghu Basin, China: Occurrence, Temporal Variations, and Ecological Risks

Antibiotics are widely used in aquaculture, however, this often results in undesirable ecological effects. To evaluate the occurrence, temporal variations, and ecological risk of antibiotics in five crab ponds of Lake Guchenghu Basin, China, 44 antibiotics from nine classes were analyzed by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS). Twelve antibiotics belonging to six classes were detected in the aqueous phase of five crab ponds, among which sulfonamides and macrolides were the predominant classes, and six compounds (sulfamonomethoxine, sulfadiazine, trimethoprim, erythromycin-H2O, monensin, and florfenicol) were frequently detected at high concentrations. In general, the antibiotic levels varied between different crab ponds, with the average concentrations ranging from 122 to 1440 ng/L. The antibiotic concentrations in crab ponds exhibited obvious seasonal variations, with the highest concentration and detection frequency detected in summer. Multivariate analysis showed that antibiotic concentrations were significantly correlated with environmental variables, such as total organic carbon, phosphate, ammonia nitrogen, and pH. Sulfadiazine, clarithromycin, erythromycin-H2O, and ciprofloxacin posed a high risk to algae, while the mixture of antibiotics could pose a high risk to aquatic organisms in the crab ponds. Overall, the usage of antibiotics in farming ponds should be comprehensively investigated and controlled to preserve a healthy aquaculture ecosystem.

Pharmacokinetic Comparisons of Typical Constituents in Curcumae Rhizoma and Vinegar-Processed Curcumae Rhizoma after Oral Administration to Rats.

The Raw Curcumae Rhizoma (R-CR), included in the Chinese Pharmacopoeia Edition 2015, is a well-known Chinese herbal medicine. However, the vinegar-processed Curcumae Rhizoma (V-CR) is used more widely than R-CR. The pharmacokinetics comparison of R-CR and V-CR after oral administration to rats is poorly understood. A novel method, rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS) coupled with a sensitive, specific, and convenient microdialysis sampling method, free from endogenous interference was developed in this research. The extracts of R-CR and V-CR were administered orally to each group of rats. The blood and liver microdialysis probes were positioned within the jugular vein toward the right atrium and the median lobe near the center of the liver, respectively. Then, a double-peak phenomenon was observed in the concentration-time curves of curdione in R-CR group, while it was not observed in V-CR group. The liver-to-blood distribution ratio of curdione in V-CR group increased significantly (P < 0.05) compared to that of R-CR group. However, compared with V-CR group, the pharmacokinetic parameters of curcumol exhibited no statistically significant differences from those of R-CR group. These results indicate that vinegar-processed procedure has influence on the pharmacokinetic process of Curcumae Rhizoma in/ns. RRLC-MS coupled with microdialysis system could be used to evaluate the pharmacokinetics of typical constituents in Curcumae Rhizoma after oral administration.

Occurrence, source analysis and risk assessment of androgens, glucocorticoids and progestagens in the Hailing Bay region, South China Sea

The occurrence and spatial distribution of 40 steroids in the environmental matrices of the Hailing Bay region, South China Sea, were investigated by rapid resolution liquid chromatography–tandem mass spectrometry (RRLC–MS/MS). Seventeen, 14 and 11 of 40 steroids were detected with the concentrations ranging from 0.04 (testosterone) to 40.00ng/L (prednisolone), 1.33 (4-hydroxy-androst-4-ene-17-dione) to 1855ng/L (androsta-1,4-diene-3,17-dione) and <0.19 (androsta-1,4-diene-3,17-dione) to 2.37ng/g (progesterone) in the seawater, the municipal sewage discharged effluent and the sediment samples, respectively. The concentrations and risk quotients (RQs) of the steroids detected in the water samples decreased in the order of municipal sewage discharge site>wharves~aquaculture zones~tourism areas>offshore areas. The distribution of steroids in the marine environment was significantly correlated with the levels of chemical oxygen demand (COD) and ammonium nitrogen (NH4-N). Source analysis indicated that untreated municipal sewage was the main source of steroids in the marine environment. Furthermore, progesterone was found to be a reliable chemical indicator to surrogate different steroids in both the water and sediment phases based on the correlation analysis.

Profiling pneumococcal type 3-derived oligosaccharides by high resolution liquid chromatography–tandem mass spectrometry

Pneumococcal type-3 polysaccharide (Pn3P) is considered a major target for the development of a human vaccine to protect against Streptococcus pneumoniae infection. Thus, it is critical to develop methods for the preparation and analysis of Pn3P-derived oligosaccharides to better understand its immunological properties. In this paper, we profile oligosaccharides, generated by the free radical depolymerization of Pn3P, using liquid chromatography (LC)–tandem mass spectrometry (MS/MS). Hydrophilic liquid interaction chromatography (HILIC)–mass spectrometry (MS) revealed a series of oligosaccharides with an even- and odd-number of saccharide residues, ranging from monosaccharide, degree of polymerization (dp1) to large oligosaccharides up to dp 20, generated by free radical depolymerization. Isomers of oligosaccharides with an even number of sugar residues were easily separated on a HILIC column, and their sequences could be distinguished by comparing MS/MS of these oligosaccharides and their reduced alditols. Fluorescent labeling with 2-aminoacridone (AMAC) followed by reversed phase (RP)-LC–MS/MS was applied to analyze and sequence poorly separated product mixtures, as RP-LC affords higher resolution of AMAC-labeled oligosaccharides than does HILIC-based separation. The present methodology can be potentially applied to profiling other capsular polysaccharides.

LC–MS/MS determination and pharmacokinetic study of seven flavonoids in rat plasma after oral administration of Cirsium japonicum DC. extract

Ethnopharmacological relevanceCirsium japonicum DC., a Traditional Chinese Medicine, has the curative effect of antihemorrhagic and antitumor. Pharmacological studies prove that the curative effect may relate to the flavonoids. A simple and rapid resolution liquid chromatography–tandem mass spectrometry (LC–MS/MS) method was first developed and validated for the quantification of seven flavonoids including pectolinarin, linarin, pectolinarigenin, hispidulin, diosmetin, acacetin and apigenin in rat plasma after oral administration of Cirsium japonicum DC. extract. Materials and methodsThe chromatographic separation was achieved on a C18 column with gradient elution by using a mixture of 0.1% formic acid aqueous solution and methanol as the mobile phase at a flow rate of 0.8mL/min. A tandem mass spectrometric detection was conducted using multiple-reaction monitoring (MRM) via an electrospray ionization (ESI) source in positive and negative ionization mode simultaneously. Samples were pre-treated by a single-step protein precipitation with methanol, and sulfamethoxazole was used as internal standard (IS). ResultsThe optimized mass transition ion-pairs (m/z) for quantization were 623.4/315.2 for pectolinarin, 593.3/285.1 for linarin, 315.3/300.2 for pectolinarigenin, 301.2/286.2 for hispidulin, 301.2/258.2 for diosmetin, 283.0/267.9 for acacetin, 269.0/117.0 for apigenin and 252.2/155.8 for IS. After oral administration of 6mL/kg Cirsium japonicum DC. extract in rats, the maximum plasma concentration (Cmax) of pectolinarin, linarin, pectolinarigenin, hispidulin, diosmetin, acacetin and apigenin were 876.77±97.34ng/mL, 86.79±1.70ng/mL, 6.13±0.12ng/mL, 32.85±2.50ng/mL, 37.2±2.04ng/mL, 19.02±1.29ng/mL and 148.26±20.63ng/mL, respectively. The time to reach the maximum plasma concentration (Tmax) was 5min for pectolinarin, linarin, pectolinarigenin, hispidulin, diosmetin, acacetin and 360min for apigenin. The intra-day and inter-day precisions (RSD%) for seven compounds were less than 13.16% and 7.77% and the accuracy (RE%) range from −7.92% to 14.77%. ConclusionsThis is the first research on the pharmacokinetic study of bioactive components in rat plasma after oral administration of Cirsium japonicum DC. extract. The results provided a meaningful basis for better understanding the absorption mechanism of Cirsium japonicum DC. and evaluating the clinical application of this herb medicine.

Steroids in marine aquaculture farms surrounding Hailing Island, South China: Occurrence, bioconcentration, and human dietary exposure

The occurrence, bioconcentration, and human dietary exposure via seafood consumption of 24 steroids were investigated by rapid resolution liquid chromatography–tandem mass spectrometry (RRLC–MS/MS) in six typical marine aquaculture farms surrounding Hailing Island, South China. Ten, 9, 10, 15 of 24 steroids were detected at concentrations ranging from <0.1 (testosterone) to 40ng/L (prednisolone), from 0.1 (4-androstene-3,17-dione) to 2.4ng/g (progesterone), from 0.3ng/g (testosterone) to 21.4ng/g (epi-androsterone), and from <0.1 (testosterone) to 560ng/g (cortisol) (wet weight) in the water, sediment, feed and biota samples, respectively. Synthetic steroids (androsta-1,4-diene-3,17-dione, 17α-boldenone, 17β-boldenone, 17β-trenbolone, prednisolone, norgestrel) were detected in the feed samples, clearly demonstrating the illegal use of steroids in the feed. The field bioconcentration factors (BCFs) of steroids calculated in different aquatic organisms ranged from 93.8 to 4000. The estimated daily intakes (EDIs) of androgens, glucocorticoids, and progestagens via consumption of seafood (i.e., shrimps, crabs, mollusks, and fish) for different age groups were in the range of 33.4–134, 2061–8566, and 40.4–155ng/d for children (2–5years), youth (6–18years), and adults (>18years), respectively. Even though no significant risk from dietary exposure arises from individual steroid, elevated risk to humans can result from the occurrence of multiple steroids in the seafood raised in the aquaculture farms, especially for the sensitive populations, such as pregnant women and children.

Determination of 15 sedative residues in mutton by rapid resolution liquid chromatography–tandem mass spectrometry

The use of xenobiotic compounds in animal husbandry has given rise to consumer anxieties regarding residual risk and food safety. Thus, animal tissues have become main samples for residue analysis and food safety for sedatives. In this study, a rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) method was established for the determination of 15 sedatives residues in mutton. After enzymolysis, sedatives residues in mutton were extracted by ammonium hydroxide-acetonitrile (10:90, v/v) and determined by RRLC-MS/MS with quantification by standard curve method. The calibration curves showed good linearity within the concentrations of 0.5-50 µg kg(-1) with the correlation coefficients (r(2)) ranged from 0.9639 to 0.9984. The limits of detection (LODs) and quantification (LOQs) were 0.25-2.5 and 0.5-5 µg kg(-1), respectively. The average recoveries of spikes samples were in the ranges of 74.1-116.8% with relative standard deviations of intra- and inter-day ranged from 2.6% to 11.2% and from 2.1% to 11.4%, respectively. This method is simple, sensitive and accurate in the determination of sedative residues.

Determination of Nine Anti-allergy Drugs Residue in Cosmetics by Solid Phase Extraction-Rapid Resolution Liquid Chromatography-Tandem Mass Spectrometry

建立了固相萃取-超快速液相色谱-串联质谱法（SPE-RRLC-MS/MS）同时测定化妆品中9种抗过敏药物残留（多西拉敏、美沙吡林、曲吡那敏、溴苯那敏、苯海拉明、赛克利嗪、二苯拉林、羟嗪和氯苯沙明）的方法。试样经三氯乙酸溶液超声提取、离心、Plexa PCX柱净化后,以甲醇-0.1%甲酸溶液（含5 mmol/L甲酸铵）为流动相,用RRLC进行分离。在电喷雾正离子模式下,以选择反应监测（SRM）方式采集数据进行定性与定量分析。9种药物在1.0～50.0!g/L范围内均呈良好的线性关系,相关系数均大于0.99;在2.0,5.0和20.0!g/kg3个浓度加标水平下的平均回收率为90.6%～103.5%;相对标准偏差（RSD,n=6）为2.5%～6.0%;检出限为0.3～0.6!g/kg,定量限为1.0～2.0!g/kg。

QuEChERS-based extraction procedure and rapid resolution liquid chromatography coupled to triple quadrupole mass spectrometry for the determination of nine mycotoxins in cereal-based complementary foods for infants and young children

A rapid method has been developed for the determination of aflatoxins B1, B2, G1 and G2, ochratoxin A, zearalenone, T-2 toxin, deoxynivalenol and fumonisin B1 in cereal-based complementary foods for infants and young children. The mycotoxins were extracted from the samples using a modified QuEChERS-based extraction procedure without any further clean-up step. The separation of the analytes was carried out on an Agilent XDB C18 column (50 mm x 2.1 mm, 1.8 microm) using the mobile phases of acetonitrile and 5 mmol/L ammonium acetate-0.1% (volume percentage) formic acid aqueous solution with gradient elution. The extract was determined by rapid resolution liquid chromatography-tandem mass spectrometry. Matrix-matched calibration was used for the quantification. The proposed method showed good linear correlation with the correlation coefficients all above 0.98. The blank samples were fortified at three levels, and the recoveries ranged from 77.6% to 105.7% with the RSDs from 2.5% to 13.7%. The limits of detection ranged from 0.1 microg/kg to 15.8 microg/kg. The developed method was successfully applied for mycotoxin analysis in 41 samples bought from markets. The method shows advantages in both accuracy and sensitivity, and is suitable for the rapid multi-aflatoxin screening in cereal-based complementary foods for infants and young children.