The aim of this work was to develop a liquid chromatography-tandem mass spectrometry method for the determination of milk allergen and egg allergen in food products.Signature peptides GGLEPINFQTAADQAR,VGINYWLAHK,VLVLD...The aim of this work was to develop a liquid chromatography-tandem mass spectrometry method for the determination of milk allergen and egg allergen in food products.Signature peptides GGLEPINFQTAADQAR,VGINYWLAHK,VLVLDTDYK,FFVAPFPEVFGK,and NAVPITPTLNR were confirmed and synthesized as the quantitative peptide of ovalbumin,α-lactalbumin,β-lactoglobulin,α_(S1)-casein andα_(S2)-casein,the relative isotope-labeled internal standards were used in the quantitative analysis.Linear range was in the range of0.5-5000.0 nmol/L for egg and milk allergen in bread,cake,cookie,rice crust and wheat flour samples with free from egg and milk,the limits of detection of milk allergens and egg allergen were in the range between0.94 mg/100 g and 56.71 mg/100 g,limits of quantification of milk allergens and egg allergen were in the range between 2.36 mg/100 g and 141.78 mg/100 g.The recoveries ranged from 76.7%to 122.8%,the relative standard deviations were in the range of 1.60%-15.60%.The developed method has been successfully used for the detection of egg and milk allergen in various food samples.展开更多
[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-g...[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-glucuronidase and extracted with 5%acetic acid-acetonitrile(1:99,V/V)solution.An Eclipse plus C 18 column was used for separation,and the MRM mode was used for qualitative analysis,and the external standard method was used for quantitative analysis of matrix standard solutions.[Results]Under the optimal conditions,the retention time of the 14 kinds ofβ-receptor agonists ranged from 1.0 to 9.5 min.When the mass concentration was in the range of 0.05-0.50μg/ml,the linear relationship ofβ-receptor agonists was good,with correlation coefficients(r)≥0.9992.The detection limits of the method were in the range of 0.04-0.87μg/kg,and the quantitative limits were in the range of 0.35-1.86μg/kg.The average recovery values were in the range of 82.8%-108.9%,with RSDs(n=6)in the range of 1.9%-6.7%.[Conclusions]The method is simple,sensitive,reproducible,accurate,and can be used for simultaneous determination of the 14 kinds ofβ-receptor agonist residues in mutton.展开更多
Objective To establish a rapid,sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of acyclovir (the metabolite of valacyclovir hydrochloride) in human plasma...Objective To establish a rapid,sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of acyclovir (the metabolite of valacyclovir hydrochloride) in human plasma. Methods After addition of ganciclovir as internal standard (IS),plasma samples were prepared by one-step protein precipitation using acetonitrile as precipitant,followed by an isocratic elution with 0.1% formic acid solution-methanol (95∶5,v/v) on an Agilent ZORBAX SB-C18 (150mm×2.1mm i.d.,3.5μm) column. Detection was performed on a triple-quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operating in positive ion and selected reaction monitoring (SRM) mode with the precursor to product ion transitions m/z 226.2→152.1 for acyclovir and m/z 256.2→152.1 for the IS. Results The analytical results demonstrated a good linearity over the ranges from 0.005 to 4μg/mL (r=0.9999) for valacyclovir hydrochloride. The relative standard deviations (RSD) of intra-batch and inter-batch were less than 4.06% and 9.23%,respectively. The limit of detection and lower limit of quantification in human plasma were 2ng/mL and 5ng/mL,respectively. Conclusion The method was simple,sensitive,accurate and reproducible and has been successfully applied to a bioequivalence study of valacyclovir hydrochloride capsules in Chinese healthy male volunteers.展开更多
[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The ...[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The samples were extracted with an acetonitrile water solution(8∶2),0.1 mol/L hydrochloric acid and a purification extraction bag with shaking.Centrifugation was performed to obtain supernatants,which were added to purification tubes containing PSA and C_(18) for purification,and then filtered with membranes for determination.Each test solution was separated by a ZORBAX Eclipse plus C_(18) column with acetonitrile and 5 mmol/L ammonium acetate as mobile phases,and determined with electrospray ionization and multiple reaction monitoring.[Results]The method had good linearity in the concentration range of 1.0-50 ng/ml,and the correlation coefficient was 0.9997.The limit of detection was 0.25μg/kg and the limit of quantification was 0.75μg/kg.The recovery was between 87.4%and 112.5%,and the RSD%was between 0.5%and 10.0%.[Conclusions]The method has simple operation and high sensitivity,and is suitable for trace detection of sodium pentachlorophenoxide in large quantities of animal-derived food.展开更多
A highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of vancomycin (VAN) in low volumes of rabbit serum. For each analysis,...A highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of vancomycin (VAN) in low volumes of rabbit serum. For each analysis, 2 μL rabbit serum was precipitated with methanol that contained the internal standard teicoplanin (TEI). The supernatant was transferred into a 384 well-plate, diluted with water, covered with a pierceable silicone mat and 5 μL was analyzed in positive ionization mode. The UHPLC-MS/MS consisted of an Agilent 1290 Infinity UHPLC system connected to an AB Sciex QTrap®5500 hybrid linear ion-trap triple quadrupole mass spectrometer equipped with a Turbo Spray source. Chromatographic separation was achieved using a Waters Acquity UPLC BEH C18 (1.7 μm, 2.1 mm × 100 mm) column, a VanGuard (1.7 μm, 2.1 × 5 mm) guard column and a mobile phase of water and methanol both containing 5 mM ammonium acetate with 0.1% formic acid. VAN was quantified with multiple reaction monitoring using the transitions of m/z 725.5/144.2, and TEI was monitored at m/z 940.6/316.4. The accuracy, precision, linearity, range and lower limit of quantification (LLOQ) were determined. The accuracy was ≤9.93% and the precision was ≤10.6%. The range was established as 0.1 to 40 μg·mL-1. The LLOQ was 0.1 μg·mL-1 VAN requiring 2 μL of sample with an accuracy of -20.2% and precision of 8.39%. The method was applied successfully to determine the VAN concentrations in rabbit serum after the i.v. administration of VAN via implanted ear catheters.展开更多
A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was built to determine icarside,hyperoside and psoralen in food.The samples were extracted with 70%methanol,the solid and semi-solid ...A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was built to determine icarside,hyperoside and psoralen in food.The samples were extracted with 70%methanol,the solid and semi-solid hotpot seasoning samples were purified by solid phase extraction column,and then determined by HPLC-MS/MS.Acetonitrile and 0.1%formic acid solution were used as the mobile phase,and the gradient elution was adopted for analysis.As shown in the results,the analytes had good linearity in the range of 0.05−100 ng/mL,and the correlation coeffificients(R^(2))were greater than 0.999.In this method,the limits of quantitation(LOQ)of psoralen,icariside and hyperoside in liquid samples were 1.25,25.0 and 12.5μg/L respectively;while the LOQs of psoralen,icariside and hyperoside in solid samples and hotpot seasoning samples were 1.25,25.0 and 12.5μg/kg,respectively.The liquid beverage,solid beverage,health food(in the form of oral liquid,capsule,tablet),integrated alcoholic beverage and solid hotpot seasoning were selected as representative samples and used for method validation.The average spiked recoveries at 3 levels(LOQ,2 LOQ,10 LOQ)were in the range of 83.7%−115.0%,and the relative standard deviations were in range of 0.5%−9.4%(n=6).The method is rapid,accurate and sensitive,which is suitable for the simultaneous determination of icariside,hyperoside and psoralen in different food matrices.展开更多
A liquid chromatography-tandem mass spectrometry method was established for the determination of ingredients of chicken,duck,pork,beef and mutton.A total of 19 characteristic peptides were screened out from 5 kinds of...A liquid chromatography-tandem mass spectrometry method was established for the determination of ingredients of chicken,duck,pork,beef and mutton.A total of 19 characteristic peptides were screened out from 5 kinds of meat,and a liquid chromatography-tandem mass spectrometry method was established for the determination of characteristic peptides.The accuracy of the method was tested by adding duck,pork and chicken with the mass fractions of 0.5%,1%and 5%to mutton,pork and chicken with the mass fractions of 0.5%,1%and 5%to beef,and duck with the mass fractions of 1%,2%and 10%to beef.The results show that the method has high accuracy and stability,and could be used to determine the content of 3 kinds of adulterated meat components in mutton and beef samples.展开更多
AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three...AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three liquefied after-cataracts were exposed to depolymerizing reagents to extract the total proteins. Protein concentrations were separated using two-dimensional gel electrophoresis(2-DE). The digitized images obtained with a GS-800 scanner were then analyzed with PDQuest7.0 software to detect the differentially-expressed protein spots. These protein spots were cut from the gel using a proteome work spot cutter and subjected to in-gel digestion with trypsin. The digested peptide separation was conducted by LC-MS/MS.RESULTS: The 2-DE maps showed that lens proteins were in a p H range of 3-10 with a relative molecular weight of 21-70 kD. The relative molecular weight of the more abundant proteins was localized at 25-50 kD, and the isoelectric points were found to lie between PI 4-9. The maps also showed that the protein level within the liquefied after-cataracts was at 29 points and significantly lower than in normal lenses. The 29 points were identified by LC-MS/MS, and ten of these proteins were identified by mass spectrometry and database queries: beta-crystallin B1, glyceraldehyde-3-phosphate dehydrogenase, carbonyl reductase(NADPH) 1, cDNA FLJ55253, gamma-crystallin D, GAS2-like protein 3, sorbitol dehydrogenase, DNA FLJ60282, phosphoglycerate kinase, and filensin. CONCLUSION: The level of the ten proteins may play an important role in the development of liquefied aftercataracts.展开更多
BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients a...BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM.展开更多
[Objectives]This study was conducted to explore the occurrence levels of endocrine disruptors(EDCs)in rural areas around a county landfill in Tongren City.[Methods]The water around the landfill was sampled and analyze...[Objectives]This study was conducted to explore the occurrence levels of endocrine disruptors(EDCs)in rural areas around a county landfill in Tongren City.[Methods]The water around the landfill was sampled and analyzed.A solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for the determination of 27 EDCs.After the HLB solid-phase extraction column was activated,a water sample,which was adjusted with phosphoric acid to a pH of 2(±0.5)and added with 500 mg of disodium EDTA,was loaded,and 5 ml of water and 20%methanol water was added for washing.Next,10 ml of elution solution was added for elution,and the collected eluate was evaporated under reduced pressure at 40℃to near dryness,and 1 ml of reconstitution solution was added to a constant volume.An ACQUITY UPLC BEH C18(100×2.1 mm,2.6μm)chromatographic column was adopted for LC separation by gradient elution with pure water solution-acetonitrile as the mobile phase.For MS detection,the MRM mode was adopted for collection,and the positive and negative ion modes were switched for simultaneous determination,and the internal standard method was used for quantification.[Results]The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance.The limits of quantitation in the method were between 0.05 and 2.00 ng/L,and the recoveries ranged from 75.3%to 105.7%.[Conclusions]The method has high sensitivity,good accuracy and strong practical value.展开更多
A precise and reliable analytical method of high performance liquid chromatography-tandem mass spectrometry(HPLCMS/MS)was developed to measure trace levels of enrofloxacin(ENR)and its major metabolite ciprofloxacin(CI...A precise and reliable analytical method of high performance liquid chromatography-tandem mass spectrometry(HPLCMS/MS)was developed to measure trace levels of enrofloxacin(ENR)and its major metabolite ciprofloxacin(CIP)in carp tissues.Optimized chromatographic separation was obtained on a Waters Xterra MS C_(18) reversed-phase column using gradient elution with methanol and 0.1%formic acid aqueous solution including 5mmolL^(-1) of ammonium acetate.The established method was applied to study the pharmacokinetics and distribution of ENR and CIP in tissues of carp following a single oral administration in feed at a dosage of 40mgkg^(-1) bw(body weight).Data were analyzed using DAS 2.0 dynamics software,and the experimental results suggest that ENR was rapidly absorbed and extensively distributed in carp tissues through systemic circulation,and the pharmacokinetic characteristics can be described with a two-compartment model.The elimination half-lives(t_(1/2β))from muscle,liver,gill,plasma and skin were 131,160,104,132 and 310 h,respectively.The areas under the drug concentration-time curves(AUC)for these tissues were 491,972,750,249 and 706hmgkg^(-1),respectively.The maximum concentration(C_(max))values were 13,29,37,9 and 5mgkg^(-1) with peak times(t_(max))of 8,4,4,2 and 4 h,respectively.Ciprofloxacin,the active metabolite of ENR,was also detected in carp tissues,indicating that only 1.54%of de-ethylation of ENR occurs in carp.At a water temperature of 18℃,the drug withdrawal time was determined to be no less than 24 d while the carp was fed at a single dosage of 40mgkg^(-1).展开更多
This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum ba...This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.展开更多
Stereoisomeric hexoses are present in almost all biological organisms in the forms of aldoses and ketoses,with diverse physi-ological and pathophysiological functions.Accurate and simultaneous quantification is vital ...Stereoisomeric hexoses are present in almost all biological organisms in the forms of aldoses and ketoses,with diverse physi-ological and pathophysiological functions.Accurate and simultaneous quantification is vital for understanding their functions individually.However,such analysis remains challenging owing to their highly similar behavior in chromatography and mass spectrometry.By combining the pre-column 3-nitrophenylhydrazine derivatization and ultrahigh performance liquid chroma-tography tandem mass spectrometry(UHPLC-MS/MS),here,we developed a method for simultaneous quantification of five important stereoisomeric hexoses including D-glucose,D-galactose,D-mannose,D-fructose and L-sorbose representing both aldoses and ketoses.The method achieved baseline-separation for all these five derivatized hexoses chromatographically and had high sensitivity(LOD,femtomole on column),excellent linearity(R2>0.995)and efficiency with stable-isotope dilution.With this method,we further quantified these hexoses in nine biological matrices including human biofluids(serum,urine and saliva),human cells,human and mouse feces,rat liver tissue,mung-bean seeds and peach pulp.The results provided quantitative data for these hexoses in multiple biological samples and showed significant concentration diversity for these hexoses in different biological samples,which demonstrated the applicability of the method for simultaneous quantification of these hexose phenotypes of biological systems.展开更多
To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrume...To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrument,then the supernatant was send to sampler for detection.Sample was chromatographed using 0.4%HAc solution-MeOH (35:65,by volume) mobile phase on an Xterra MS C18 column.Analyte determination was performed by ESI MS/MS in the multiple reaction monitoring(MRM)mode.The established method of LC-MS/MS determining the concentration of osthole in food additive has the characteristic of strong specificity,high sensitivity and good reproducibility.The linear range of papaverine was 0.001-10 μg/mL,method recovery was 97.42%,RSD was 8.37%,the limit of detection was 1 ng/mL and the limit of quantitation was 0.001 μg/mL.展开更多
A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC...A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC-MS/MS),and their distribution characteristics were investigated.DA concentration was detected high in over 1/3(36.1%)of the samples of four kinds of shellfish in all three seasons in range from 0 to 102μg/kg.The highest DA concentrations were 102,101,36.7,and 10.2μg/kg in Crassostrea gigas,Chlamys farreri,Mactra veneriformis,and Mytilus edulis,respectively.Geographically,Yantai(22.0μg/kg)and Weihai(16.9μg/kg)showed relatively high concentrations of DA,whereas Rizhao and Dongying presented only 0.85-and 1.76-μg/kg DA,respectively.DA concentrations in the shellfish samples were strongly related to seasonal changes,being significantly higher in autumn and summer than that in spring.The DA risk exposure assessments indicate that dietary seafood consumption did not pose a health threat to general human population.In addition,three isomers(isoA,isoD,isoE)and 5′-epimer DA were detected in 3.00%-15.80%of the shellfish samples.This study is the first to observe DA and its isomers in shellfish samples of Shandong Province.The results demonstrate that DA contamination is very common and should be continuously monitored.展开更多
[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theorie...[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theories such as Evaluation and expression of uncertainty in measurement,the uncertainty in the results of nitrofuran metabolites in chicken bone was analyzed and calculated combining with mathematical models. [Results] Under the addition amount of 1. 0 μg/kg,the uncertainty of the four nitrofuran metabolites was as follows: nitrofurazone metabolites C(SEM)= 0. 981 μg/kg,U = 0. 070 μg/kg,k = 2;furazolidone metabolites C(AOZ)= 1. 032 μg/kg,U = 0. 061 μg/kg,k = 2;furaltadone metabolites C(AMOZ)= 1. 068 μg/kg,U = 0. 076 μg/kg,k = 2;furadantin metabolites C(AHD)=1. 007 μg/kg,U = 0. 046 μg/kg,k = 2. [Conclusions]The uncertainty in the measurement process mainly comes from the purity of the standards,the preparation process,the sample weight,the number of repeated measurement and the recovery of spiked sample. The research results are of great significance for reducing uncertainty and improving data accuracy and reliability during actual operation.展开更多
[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass ...[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.展开更多
Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from ...Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from coastal waters of Weihai in Shandong Peninsula,China in autumn,2020,and screened for lipophilic marine toxins and their potential producers using liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis and high throughput sequencing of partial DNA(V4 region of the 18S rRNA gene)extracted from phytoplankton.Pectenotoxin-2(PTX2),trace amounts of azaspiracid(AZA1 or AZA40),and 13-desmethyl spirolide C(13-DesMe-C)were detected in phytoplankton samples,while PTX2 and gymnodimine(GYM)were detected in shellfish samples.The toxin content in shellfish samples was much lower than the regulatory limit or values reported previously.Results suggest that lipophilic marine toxins should have low risk in coastal waters of Weihai in autumn.Based on the data of high throughput sequencing,the OTUs were assigned to 5 identified species of Alexandrium,including A.ostenfeldii capable of producing 13-DesMe-C and GYM.Two OTUs were found closely related to the toxic species in genus Dinophysis,but it is impossible to assign them to any identified species due to the low resolving power of the V4 region for Dinophysis.The OTUs could not be assigned to any identified species in the genus Azadinium,suggesting the existence of unidentified species in this region.展开更多
Drug-facilitated sexual assault(DFSA)is a sexual act in which the victim is unable to give or rescind consent due to alcohol or drug intoxication,which involved the abuse of benzodiazepines around the world.Convention...Drug-facilitated sexual assault(DFSA)is a sexual act in which the victim is unable to give or rescind consent due to alcohol or drug intoxication,which involved the abuse of benzodiazepines around the world.Conventional techniques used for the analysis of benzodiazepines have the limitation of short detection time window due to the rapid metabolism of these drugs in body.This study aimed to investigate the characteristic changes of metabolites in the blood of rats after ingesting diazepam/clonazepam through a gas chromatography-mass spectrometry-based metabolomics method,allowing the indirect reveal of the rats ingested diazepam/clonazepam.First,we found that diazepam and clonazepam in the blood of rats could not be detected by liquid chromatography-tandem mass spectrometry after 48 h of ingestion.Then,orthogonal partial least squares discrimination analysis regression models were,respectively,constructed to determine whether the rats ingested diazepam/clonazepam after 48 h.The results showed that 5 metabolites were found to be associated with diazepam exposure,and 7 metabolites were found to be associated with clonazepam exposure,which may be characterization for the evaluation of digestion of diazepam and clonazepam in rat.展开更多
[Objectives]This study was conducted to provide an accurate and reliable method for rapid high-throughput screening of veterinary drug preparations.[Methods]For the matrixes of veterinary drug preparations,high-perfor...[Objectives]This study was conducted to provide an accurate and reliable method for rapid high-throughput screening of veterinary drug preparations.[Methods]For the matrixes of veterinary drug preparations,high-performance liquid chromatography-high resolution quadrupole time-of-flight mass spectrometry(UPLC-QTOF/MS)was used to establish a fast screening method for 59 non-standard components in five categories of antiviral agents,aminoglycosides,quinolones,sulfonamides,and tetracyclines in veterinary drugs.The target drugs were separated by a Waters ACQUITY UPLC HSS T3 chromatographic column(50 mm×2.1 mm,1.8μm),and data were collected in the positive ion mode.Good separation of the 59 drugs was achieved within 7 min.[Results]In the concentration range of 0-100 ng/ml,each drug showed a good linear relationship,and the correlation coefficients were all greater than 0.999.The detection limits of the 59 drugs were in the range of 0.1-0.5 mg/ml,and the recovery under the addition concentration of 5 mg/ml was in the range of 85.2%-103.8%.[Conclusions]The method is fast,simple,accurate,and highly sensitive,and is suitable for high-throughput screening and qualitative identification of non-standard components in veterinary drug preparations.展开更多
基金supported by National Key Research and Development Program of China(2019YFC1606400)Science and Technology Project of State Administration for Market Regulation(2021MK023)+1 种基金Hebei Province High-level Talent Funding Program(A201901008)Research Project of Hebei Administration for Market Regulation(2020ZD12)。
文摘The aim of this work was to develop a liquid chromatography-tandem mass spectrometry method for the determination of milk allergen and egg allergen in food products.Signature peptides GGLEPINFQTAADQAR,VGINYWLAHK,VLVLDTDYK,FFVAPFPEVFGK,and NAVPITPTLNR were confirmed and synthesized as the quantitative peptide of ovalbumin,α-lactalbumin,β-lactoglobulin,α_(S1)-casein andα_(S2)-casein,the relative isotope-labeled internal standards were used in the quantitative analysis.Linear range was in the range of0.5-5000.0 nmol/L for egg and milk allergen in bread,cake,cookie,rice crust and wheat flour samples with free from egg and milk,the limits of detection of milk allergens and egg allergen were in the range between0.94 mg/100 g and 56.71 mg/100 g,limits of quantification of milk allergens and egg allergen were in the range between 2.36 mg/100 g and 141.78 mg/100 g.The recoveries ranged from 76.7%to 122.8%,the relative standard deviations were in the range of 1.60%-15.60%.The developed method has been successfully used for the detection of egg and milk allergen in various food samples.
基金Supported by The Fourth Batch of High-end Talent Project in Hebei ProvinceTangshan Science and Technology Entrepreneurship and Innovation Leading Talent Project(21130243A).
文摘[Objectives]A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was established for the determination of 14β-receptor agonist residues in mutton.[Methods]Samples were hydrolyzed byβ-glucuronidase and extracted with 5%acetic acid-acetonitrile(1:99,V/V)solution.An Eclipse plus C 18 column was used for separation,and the MRM mode was used for qualitative analysis,and the external standard method was used for quantitative analysis of matrix standard solutions.[Results]Under the optimal conditions,the retention time of the 14 kinds ofβ-receptor agonists ranged from 1.0 to 9.5 min.When the mass concentration was in the range of 0.05-0.50μg/ml,the linear relationship ofβ-receptor agonists was good,with correlation coefficients(r)≥0.9992.The detection limits of the method were in the range of 0.04-0.87μg/kg,and the quantitative limits were in the range of 0.35-1.86μg/kg.The average recovery values were in the range of 82.8%-108.9%,with RSDs(n=6)in the range of 1.9%-6.7%.[Conclusions]The method is simple,sensitive,reproducible,accurate,and can be used for simultaneous determination of the 14 kinds ofβ-receptor agonist residues in mutton.
文摘Objective To establish a rapid,sensitive and selective liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the determination of acyclovir (the metabolite of valacyclovir hydrochloride) in human plasma. Methods After addition of ganciclovir as internal standard (IS),plasma samples were prepared by one-step protein precipitation using acetonitrile as precipitant,followed by an isocratic elution with 0.1% formic acid solution-methanol (95∶5,v/v) on an Agilent ZORBAX SB-C18 (150mm×2.1mm i.d.,3.5μm) column. Detection was performed on a triple-quadrupole mass spectrometer utilizing electrospray ionization (ESI) interface operating in positive ion and selected reaction monitoring (SRM) mode with the precursor to product ion transitions m/z 226.2→152.1 for acyclovir and m/z 256.2→152.1 for the IS. Results The analytical results demonstrated a good linearity over the ranges from 0.005 to 4μg/mL (r=0.9999) for valacyclovir hydrochloride. The relative standard deviations (RSD) of intra-batch and inter-batch were less than 4.06% and 9.23%,respectively. The limit of detection and lower limit of quantification in human plasma were 2ng/mL and 5ng/mL,respectively. Conclusion The method was simple,sensitive,accurate and reproducible and has been successfully applied to a bioequivalence study of valacyclovir hydrochloride capsules in Chinese healthy male volunteers.
文摘[Objectives]This study was conducted to establish an ultra-high performance liquid chromatography-tandem mass spectrometry for the rapid extraction of sodium pentachlorophenoxide from animal-derived food.[Methods]The samples were extracted with an acetonitrile water solution(8∶2),0.1 mol/L hydrochloric acid and a purification extraction bag with shaking.Centrifugation was performed to obtain supernatants,which were added to purification tubes containing PSA and C_(18) for purification,and then filtered with membranes for determination.Each test solution was separated by a ZORBAX Eclipse plus C_(18) column with acetonitrile and 5 mmol/L ammonium acetate as mobile phases,and determined with electrospray ionization and multiple reaction monitoring.[Results]The method had good linearity in the concentration range of 1.0-50 ng/ml,and the correlation coefficient was 0.9997.The limit of detection was 0.25μg/kg and the limit of quantification was 0.75μg/kg.The recovery was between 87.4%and 112.5%,and the RSD%was between 0.5%and 10.0%.[Conclusions]The method has simple operation and high sensitivity,and is suitable for trace detection of sodium pentachlorophenoxide in large quantities of animal-derived food.
基金supported by the operating grant of the Collaborative Health Research Project,Natural Sciences and Engineering Research Council of Canada,and Canadian Institute of Health Research(CHRPJ 385967).
文摘A highly sensitive ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed for the quantification of vancomycin (VAN) in low volumes of rabbit serum. For each analysis, 2 μL rabbit serum was precipitated with methanol that contained the internal standard teicoplanin (TEI). The supernatant was transferred into a 384 well-plate, diluted with water, covered with a pierceable silicone mat and 5 μL was analyzed in positive ionization mode. The UHPLC-MS/MS consisted of an Agilent 1290 Infinity UHPLC system connected to an AB Sciex QTrap®5500 hybrid linear ion-trap triple quadrupole mass spectrometer equipped with a Turbo Spray source. Chromatographic separation was achieved using a Waters Acquity UPLC BEH C18 (1.7 μm, 2.1 mm × 100 mm) column, a VanGuard (1.7 μm, 2.1 × 5 mm) guard column and a mobile phase of water and methanol both containing 5 mM ammonium acetate with 0.1% formic acid. VAN was quantified with multiple reaction monitoring using the transitions of m/z 725.5/144.2, and TEI was monitored at m/z 940.6/316.4. The accuracy, precision, linearity, range and lower limit of quantification (LLOQ) were determined. The accuracy was ≤9.93% and the precision was ≤10.6%. The range was established as 0.1 to 40 μg·mL-1. The LLOQ was 0.1 μg·mL-1 VAN requiring 2 μL of sample with an accuracy of -20.2% and precision of 8.39%. The method was applied successfully to determine the VAN concentrations in rabbit serum after the i.v. administration of VAN via implanted ear catheters.
基金This work was supported by National Key Research and Development Program of China(2019YFC1606400).
文摘A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method was built to determine icarside,hyperoside and psoralen in food.The samples were extracted with 70%methanol,the solid and semi-solid hotpot seasoning samples were purified by solid phase extraction column,and then determined by HPLC-MS/MS.Acetonitrile and 0.1%formic acid solution were used as the mobile phase,and the gradient elution was adopted for analysis.As shown in the results,the analytes had good linearity in the range of 0.05−100 ng/mL,and the correlation coeffificients(R^(2))were greater than 0.999.In this method,the limits of quantitation(LOQ)of psoralen,icariside and hyperoside in liquid samples were 1.25,25.0 and 12.5μg/L respectively;while the LOQs of psoralen,icariside and hyperoside in solid samples and hotpot seasoning samples were 1.25,25.0 and 12.5μg/kg,respectively.The liquid beverage,solid beverage,health food(in the form of oral liquid,capsule,tablet),integrated alcoholic beverage and solid hotpot seasoning were selected as representative samples and used for method validation.The average spiked recoveries at 3 levels(LOQ,2 LOQ,10 LOQ)were in the range of 83.7%−115.0%,and the relative standard deviations were in range of 0.5%−9.4%(n=6).The method is rapid,accurate and sensitive,which is suitable for the simultaneous determination of icariside,hyperoside and psoralen in different food matrices.
基金This work was supported by National Key Research and Development Program of China(2019YFC1606400)Hebei Province High-level Talent Funding Program(A201901008)Research Project of Hebei Administration for Market Regulation(2020ZD12).
文摘A liquid chromatography-tandem mass spectrometry method was established for the determination of ingredients of chicken,duck,pork,beef and mutton.A total of 19 characteristic peptides were screened out from 5 kinds of meat,and a liquid chromatography-tandem mass spectrometry method was established for the determination of characteristic peptides.The accuracy of the method was tested by adding duck,pork and chicken with the mass fractions of 0.5%,1%and 5%to mutton,pork and chicken with the mass fractions of 0.5%,1%and 5%to beef,and duck with the mass fractions of 1%,2%and 10%to beef.The results show that the method has high accuracy and stability,and could be used to determine the content of 3 kinds of adulterated meat components in mutton and beef samples.
基金Supported by National Natural Science Foundation of China(No.81370996)
文摘AIM: To analyze and identify the proteomic differences between liquefied after-cataracts and normal lenses by means of liquefied chromatography-tandem mass spectrometry(LC-MS/MS).METHODS: Three normal lenses and three liquefied after-cataracts were exposed to depolymerizing reagents to extract the total proteins. Protein concentrations were separated using two-dimensional gel electrophoresis(2-DE). The digitized images obtained with a GS-800 scanner were then analyzed with PDQuest7.0 software to detect the differentially-expressed protein spots. These protein spots were cut from the gel using a proteome work spot cutter and subjected to in-gel digestion with trypsin. The digested peptide separation was conducted by LC-MS/MS.RESULTS: The 2-DE maps showed that lens proteins were in a p H range of 3-10 with a relative molecular weight of 21-70 kD. The relative molecular weight of the more abundant proteins was localized at 25-50 kD, and the isoelectric points were found to lie between PI 4-9. The maps also showed that the protein level within the liquefied after-cataracts was at 29 points and significantly lower than in normal lenses. The 29 points were identified by LC-MS/MS, and ten of these proteins were identified by mass spectrometry and database queries: beta-crystallin B1, glyceraldehyde-3-phosphate dehydrogenase, carbonyl reductase(NADPH) 1, cDNA FLJ55253, gamma-crystallin D, GAS2-like protein 3, sorbitol dehydrogenase, DNA FLJ60282, phosphoglycerate kinase, and filensin. CONCLUSION: The level of the ten proteins may play an important role in the development of liquefied aftercataracts.
基金This study was reviewed and approved by the Maternal and child health hospital of Hubei Province(Approval No.20201025).
文摘BACKGROUND As a well-known fact to the public,gestational diabetes mellitus(GDM)could bring serious risks for both pregnant women and infants.During this important investigation into the linkage between GDM patients and their altered expression in the serum,proteomics techniques were deployed to detect the differentially expressed proteins(DEPs)of in the serum of GDM patients to further explore its pathogenesis,and find out possible biomarkers to forecast GDM occurrence.METHODS Subjects were divided into GDM and normal control groups according to the IADPSG diagnostic criteria.Serum samples were randomly selected from four cases in each group at 24-28 wk of gestation,and the blood samples were identified by applying iTRAQ technology combined with liquid chromatography-tandem mass spectrometry.Key proteins and signaling pathways associated with GDM were identified by bioinformatics analysis,and the expression of key proteins in serum from 12 wk to 16 wk of gestation was further verified using enzyme-linked immunosorbent assay (ELISA).RESULTS Forty-seven proteins were significantly differentially expressed by analyzing the serum samples between the GDMgravidas as well as the healthy ones. Among them, 31 proteins were found to be upregulated notably and the rest16 proteins were downregulated remarkably. Bioinformatic data report revealed abnormal expression of proteinsassociated with lipid metabolism, coagulation cascade activation, complement system and inflammatory responsein the GDM group. ELISA results showed that the contents of RBP4, as well as ANGPTL8, increased in the serumof GDM gravidas compared with the healthy ones, and this change was found to initiate from 12 wk to 16 wk ofgestation.CONCLUSION GDM symptoms may involve abnormalities in lipid metabolism, coagulation cascade activation, complementsystem and inflammatory response. RBP4 and ANGPTL8 are expected to be early predictors of GDM.
基金Supported by Tongren Science and Technology Planning Project (TSKY[2022]42)Education Science Planning Project of Department of Education of Guizhou Province (2023B111).
文摘[Objectives]This study was conducted to explore the occurrence levels of endocrine disruptors(EDCs)in rural areas around a county landfill in Tongren City.[Methods]The water around the landfill was sampled and analyzed.A solid-phase extraction and high performance liquid chromatography-tandem mass spectrometry(SPE-UPLC-MS/MS)method was established for the determination of 27 EDCs.After the HLB solid-phase extraction column was activated,a water sample,which was adjusted with phosphoric acid to a pH of 2(±0.5)and added with 500 mg of disodium EDTA,was loaded,and 5 ml of water and 20%methanol water was added for washing.Next,10 ml of elution solution was added for elution,and the collected eluate was evaporated under reduced pressure at 40℃to near dryness,and 1 ml of reconstitution solution was added to a constant volume.An ACQUITY UPLC BEH C18(100×2.1 mm,2.6μm)chromatographic column was adopted for LC separation by gradient elution with pure water solution-acetonitrile as the mobile phase.For MS detection,the MRM mode was adopted for collection,and the positive and negative ion modes were switched for simultaneous determination,and the internal standard method was used for quantification.[Results]The correlation coefficient R2 was greater than 0.99 in the linear range of each target substance.The limits of quantitation in the method were between 0.05 and 2.00 ng/L,and the recoveries ranged from 75.3%to 105.7%.[Conclusions]The method has high sensitivity,good accuracy and strong practical value.
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,CAFS(No.2020TD71).
文摘A precise and reliable analytical method of high performance liquid chromatography-tandem mass spectrometry(HPLCMS/MS)was developed to measure trace levels of enrofloxacin(ENR)and its major metabolite ciprofloxacin(CIP)in carp tissues.Optimized chromatographic separation was obtained on a Waters Xterra MS C_(18) reversed-phase column using gradient elution with methanol and 0.1%formic acid aqueous solution including 5mmolL^(-1) of ammonium acetate.The established method was applied to study the pharmacokinetics and distribution of ENR and CIP in tissues of carp following a single oral administration in feed at a dosage of 40mgkg^(-1) bw(body weight).Data were analyzed using DAS 2.0 dynamics software,and the experimental results suggest that ENR was rapidly absorbed and extensively distributed in carp tissues through systemic circulation,and the pharmacokinetic characteristics can be described with a two-compartment model.The elimination half-lives(t_(1/2β))from muscle,liver,gill,plasma and skin were 131,160,104,132 and 310 h,respectively.The areas under the drug concentration-time curves(AUC)for these tissues were 491,972,750,249 and 706hmgkg^(-1),respectively.The maximum concentration(C_(max))values were 13,29,37,9 and 5mgkg^(-1) with peak times(t_(max))of 8,4,4,2 and 4 h,respectively.Ciprofloxacin,the active metabolite of ENR,was also detected in carp tissues,indicating that only 1.54%of de-ethylation of ENR occurs in carp.At a water temperature of 18℃,the drug withdrawal time was determined to be no less than 24 d while the carp was fed at a single dosage of 40mgkg^(-1).
基金funded by the Forestry Science and Technology Innovation Project of Guangdong Province,China(2020KJCX010).
文摘This study aimed to explore the anti-bacterial and anti-fungal activities of extracts from different parts of plants in the Zingiberaceae family.The inhibitory rate,minimum inhibitory concentration(MIC),and minimum bactericidal concentration(MBC)of leaf and stem,and root and rhizome extracts from Alpinia katsumadai Hayata,Alpinia oxyphylla Miq×Alpinia henryi K.Schumann,Alpinia oblongifolia Hayata,Alpinia nigra(Gaertn.)Burtt,Amomum villosum Lour,Alpinia zerumbet(Pers.)Burtt.et Smith and Alpinia oxyphylla Miq were determined using the fungus cake method and double dilution method.The seven Zingiberaceae plants exhibited characteristic antibacterial activities against pathogenic bacteria and fungi.At a 1.5 mg mL^(−1),A.zerumbet root and rhizome extracts exhibited strong inhibitory activity against S.aureus and E.coli,with 83.23%and 79.62%,respectively.In addition,A.zerumbet leaf and stem extracts had an inhibitory rate of 90.85%against P.aeruginosa.At the same concentration,the leaf and stem,root and rhizome extracts of A.katsumadai had the best anti-bacterial effect against F.oxysporum,with inhibition rates of 84.46%and 84.73%,respectively.Moreover,A.katsumadai and A.zerumbet leaf and stem extracts had the most significant antibacterial effect against S.aureus,with a MIC of 0.063 mg mL^(−1).Thus,both A.katsumadai and A.zerumbet extracts had significant antibacterial activity.In addition,by comparing the inhibitory effect of extracts from different parts,it was found that the inhibitory rate and average inhibitory rate of extracts from leaf and stem were higher than those from root and rhizome.The chemical constituents of A.katsumadai and A.zerumbet,determined by the high-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS),revealed that citric acid(CA),alpinetin,and pinocembrin(PNCB)were the functional constituents yielding the antibacterial activity.Overall,A.katsumadai and A.zerumbet have the potential to be developed as new plant fungicides and bactericides.
基金support from the National Key R&D Program of China(2017YFC0906800)Shanghai Municipal Science and Technology Major Project(2017SHZDZX01)the National Natural Science Foundation of China(81590953,31821002 and 21405020).
文摘Stereoisomeric hexoses are present in almost all biological organisms in the forms of aldoses and ketoses,with diverse physi-ological and pathophysiological functions.Accurate and simultaneous quantification is vital for understanding their functions individually.However,such analysis remains challenging owing to their highly similar behavior in chromatography and mass spectrometry.By combining the pre-column 3-nitrophenylhydrazine derivatization and ultrahigh performance liquid chroma-tography tandem mass spectrometry(UHPLC-MS/MS),here,we developed a method for simultaneous quantification of five important stereoisomeric hexoses including D-glucose,D-galactose,D-mannose,D-fructose and L-sorbose representing both aldoses and ketoses.The method achieved baseline-separation for all these five derivatized hexoses chromatographically and had high sensitivity(LOD,femtomole on column),excellent linearity(R2>0.995)and efficiency with stable-isotope dilution.With this method,we further quantified these hexoses in nine biological matrices including human biofluids(serum,urine and saliva),human cells,human and mouse feces,rat liver tissue,mung-bean seeds and peach pulp.The results provided quantitative data for these hexoses in multiple biological samples and showed significant concentration diversity for these hexoses in different biological samples,which demonstrated the applicability of the method for simultaneous quantification of these hexose phenotypes of biological systems.
文摘To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrument,then the supernatant was send to sampler for detection.Sample was chromatographed using 0.4%HAc solution-MeOH (35:65,by volume) mobile phase on an Xterra MS C18 column.Analyte determination was performed by ESI MS/MS in the multiple reaction monitoring(MRM)mode.The established method of LC-MS/MS determining the concentration of osthole in food additive has the characteristic of strong specificity,high sensitivity and good reproducibility.The linear range of papaverine was 0.001-10 μg/mL,method recovery was 97.42%,RSD was 8.37%,the limit of detection was 1 ng/mL and the limit of quantitation was 0.001 μg/mL.
基金Supported by the Science&Technology Basic Resources Investigation Program of China(No.2018FY100200)the National Natural Science Foundation of China(Nos.32072329,41976110)+1 种基金the Central PublicInterest Scientifi c Institution Basal Research Fund,CAFS(No.2020TD71)the Earmarked Fund for CARS(CARS-49)。
文摘A total of 133 shellfish samples were collected in seven cities of Shandong Province,China,from May to October,2019.The domoic acid(DA)concentrations were determined by liquid chromatographytandem mass spectrometry(LC-MS/MS),and their distribution characteristics were investigated.DA concentration was detected high in over 1/3(36.1%)of the samples of four kinds of shellfish in all three seasons in range from 0 to 102μg/kg.The highest DA concentrations were 102,101,36.7,and 10.2μg/kg in Crassostrea gigas,Chlamys farreri,Mactra veneriformis,and Mytilus edulis,respectively.Geographically,Yantai(22.0μg/kg)and Weihai(16.9μg/kg)showed relatively high concentrations of DA,whereas Rizhao and Dongying presented only 0.85-and 1.76-μg/kg DA,respectively.DA concentrations in the shellfish samples were strongly related to seasonal changes,being significantly higher in autumn and summer than that in spring.The DA risk exposure assessments indicate that dietary seafood consumption did not pose a health threat to general human population.In addition,three isomers(isoA,isoD,isoE)and 5′-epimer DA were detected in 3.00%-15.80%of the shellfish samples.This study is the first to observe DA and its isomers in shellfish samples of Shandong Province.The results demonstrate that DA contamination is very common and should be continuously monitored.
文摘[Objectives] Uncertainty in liquid chromatography-mass spectrometry detection of nitrofuran metabolite residues in chicken bone was analyzed to find out the influencing factors. [Methods] According to relevant theories such as Evaluation and expression of uncertainty in measurement,the uncertainty in the results of nitrofuran metabolites in chicken bone was analyzed and calculated combining with mathematical models. [Results] Under the addition amount of 1. 0 μg/kg,the uncertainty of the four nitrofuran metabolites was as follows: nitrofurazone metabolites C(SEM)= 0. 981 μg/kg,U = 0. 070 μg/kg,k = 2;furazolidone metabolites C(AOZ)= 1. 032 μg/kg,U = 0. 061 μg/kg,k = 2;furaltadone metabolites C(AMOZ)= 1. 068 μg/kg,U = 0. 076 μg/kg,k = 2;furadantin metabolites C(AHD)=1. 007 μg/kg,U = 0. 046 μg/kg,k = 2. [Conclusions]The uncertainty in the measurement process mainly comes from the purity of the standards,the preparation process,the sample weight,the number of repeated measurement and the recovery of spiked sample. The research results are of great significance for reducing uncertainty and improving data accuracy and reliability during actual operation.
基金Supported by Research Projects Funded by Talent Project Training Funds in Hebei Province(A201901128)Key R&D Project of Tangshan City(20150210C).
文摘[Objectives]This study was conducted to effectively monitor PGR residues in bean sprouts to provide guarantee for the food safety of agricultural products.[Methods]A high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS)method for the determination of residues of 15 plant growth regulators(PGRs)in bean sprouts was established using bean sprouts as an experimental material.Samples were extracted with a solution containing 5%acetic acid-acetonitrile(1∶99,V/V),purified with anhydrous magnesium sulfate,and diluted with methanol solvent to constant volume.The solutions were filtered through 0.22μm filtering membrane and the target analytes were separated on a Phenomenex H18 column.The identification of each compound was established by retention time matching along with the accurate mass measurement of the precursor ions and their main fragment ions.The quantification was carried out using matrix-matched external standard method.[Results]The retention time of the 15 PGRs were found in the range from 5.8-11.7 min under the optimized conditions.The linear relation was good in the concentration range of 0.005-0.050μg/ml,and the correlation coefficients of the 15 PGRs were≥0.9990.The limits of detection were in the range of 0.03-0.92 g/kg,and the limits of quantification were in the range of 0.50-2.10μg/kg.The average recovery in the recovery test at 3 concentration levels was 80%-110%,and the relative standard deviations were in the range of 2.8%-7.5%.[Conclusions]This method is simple and accurate,and can quickly qualitatively and quantitatively analyze the residues of 15 PGRs in bean sprouts.The proposed procedure was simple,quick and accurate for the simultaneous determination of the 15 PGRs in bean sprout.
基金Supported by the Pilot National Laboratory for Marine Science and Technology(No.2021QNLM040001-2)the Science and Technology Basic Resources Investigation Program(No.2018FY100200)+2 种基金the National Key R&D Program(No.2017YFC1600701)the CAS-CSIRO BAU project of the Chinese Academy of Sciences(No.GJHZ201973)the National Natural Science Foundation of China(No.42106206)。
文摘Lipophilic marine toxins(LMTs)produced by some microalgae in the sea could accumulate in shellfish and pose potential threats to the health of seafood consumers.Phytoplankton and shellfish samples were collected from coastal waters of Weihai in Shandong Peninsula,China in autumn,2020,and screened for lipophilic marine toxins and their potential producers using liquid chromatography-tandem mass spectrometry(LC-MS/MS)analysis and high throughput sequencing of partial DNA(V4 region of the 18S rRNA gene)extracted from phytoplankton.Pectenotoxin-2(PTX2),trace amounts of azaspiracid(AZA1 or AZA40),and 13-desmethyl spirolide C(13-DesMe-C)were detected in phytoplankton samples,while PTX2 and gymnodimine(GYM)were detected in shellfish samples.The toxin content in shellfish samples was much lower than the regulatory limit or values reported previously.Results suggest that lipophilic marine toxins should have low risk in coastal waters of Weihai in autumn.Based on the data of high throughput sequencing,the OTUs were assigned to 5 identified species of Alexandrium,including A.ostenfeldii capable of producing 13-DesMe-C and GYM.Two OTUs were found closely related to the toxic species in genus Dinophysis,but it is impossible to assign them to any identified species due to the low resolving power of the V4 region for Dinophysis.The OTUs could not be assigned to any identified species in the genus Azadinium,suggesting the existence of unidentified species in this region.
基金The study was financially supported by the Project of the National Natural Sciences Foundation of China(81373239)The Innovation and Business Starting-oriented training program of College Students in Sichuan Province(C2020113713).
文摘Drug-facilitated sexual assault(DFSA)is a sexual act in which the victim is unable to give or rescind consent due to alcohol or drug intoxication,which involved the abuse of benzodiazepines around the world.Conventional techniques used for the analysis of benzodiazepines have the limitation of short detection time window due to the rapid metabolism of these drugs in body.This study aimed to investigate the characteristic changes of metabolites in the blood of rats after ingesting diazepam/clonazepam through a gas chromatography-mass spectrometry-based metabolomics method,allowing the indirect reveal of the rats ingested diazepam/clonazepam.First,we found that diazepam and clonazepam in the blood of rats could not be detected by liquid chromatography-tandem mass spectrometry after 48 h of ingestion.Then,orthogonal partial least squares discrimination analysis regression models were,respectively,constructed to determine whether the rats ingested diazepam/clonazepam after 48 h.The results showed that 5 metabolites were found to be associated with diazepam exposure,and 7 metabolites were found to be associated with clonazepam exposure,which may be characterization for the evaluation of digestion of diazepam and clonazepam in rat.
基金Supported by Key R&D Project of Hebei Province(19227516D)Hebei Provincial Phase II Modern Agricultural Industry Technology System Innovation Team Building Project(HBCT2018120207)+2 种基金Hebei Provincial Phase II Modern Agricultural Industry Technology System Grass Industry Innovation Team Building Project(HBCT2018160403)Hebei Provincial Science and Technology Innovation Leading Talents(21130243A)The Fourth Batch of High-end Talent Project in Hebei Province。
文摘[Objectives]This study was conducted to provide an accurate and reliable method for rapid high-throughput screening of veterinary drug preparations.[Methods]For the matrixes of veterinary drug preparations,high-performance liquid chromatography-high resolution quadrupole time-of-flight mass spectrometry(UPLC-QTOF/MS)was used to establish a fast screening method for 59 non-standard components in five categories of antiviral agents,aminoglycosides,quinolones,sulfonamides,and tetracyclines in veterinary drugs.The target drugs were separated by a Waters ACQUITY UPLC HSS T3 chromatographic column(50 mm×2.1 mm,1.8μm),and data were collected in the positive ion mode.Good separation of the 59 drugs was achieved within 7 min.[Results]In the concentration range of 0-100 ng/ml,each drug showed a good linear relationship,and the correlation coefficients were all greater than 0.999.The detection limits of the 59 drugs were in the range of 0.1-0.5 mg/ml,and the recovery under the addition concentration of 5 mg/ml was in the range of 85.2%-103.8%.[Conclusions]The method is fast,simple,accurate,and highly sensitive,and is suitable for high-throughput screening and qualitative identification of non-standard components in veterinary drug preparations.
