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Background The production and consumption of high polar pesticides in China are the largest in the world. Therefore, it is urgent to develop a method with fast analysis, large flux, and high accuracy to determine the residues of these pesticides in food. Objective To establish a method for the determination of eight highly polar pesticides [chlormequat, paraquat, difenzoquat, cyromazine, propamocarb, glyphosate, (aminomethyl)-phosphonic acid, and glufosinate] in vegetables and fruits by ultra-performance liquid chromatography-tandem mass spectrometry. Methods After comparing various types of hydrophilic interaction liquid chromatography (HILIC) columns, and optimizing pH value and buffer concentration of mobile phase, effective chromatographic retention and separation of selected eight pesticides were achieved. Based on the optimization of mass spectrometry under chromatographic conditions, a multiple reaction monitoring (MRM) channel of target compounds was established. In the sample pretreatment, through optimization of water content, extraction solvent, and purification method, a final MRM mode of ultra-performance liquid chromatography-tandem mass spectrometry was used for detection, and the isotope internal standard method was used for quantification. The accuracy and the precision of the method were evaluated using recovery and relative standard deviation. The established method was applied to detect 57 samples of retail vegetables and fruits to investigate the adaptability of the proposed method and the residual levels of selected high polar pesticides. Results For positive ion electrospray ionization (ESI+) detection, we chose Sielc Obelisc R as chromatographic column, and 20 mmol·L−1 ammonium formate solution (pH=3±0.05) and acetonitrile as mobile phase; for negative ion electrospray ionization (ESI−) detection, we chose Shodex Asahipak NH2P-50 2D as chromatographic column, and 5 mmol·L−1 ammonium acetate solution (pH=11±0.05) and acetonitrile as mobile phase to obtain good chromatographic separation and peak shape. Under the optimal conditions of sample water content standardization, using 2% acidified methanol as extraction solvent, and C18 dispersed solid phase extraction purification, the linearity ranges of five analytes (chlormequat, paraquat, difenzoquat, cyromazine, and propamocarb) and three analytes [glyphosate, (aminomethyl)phosphonic acid, and glufosinate] were 1.00-100 μg·L−1 and 5.00-500 μg·L−1 (both correlation coefficients>0.999) respectively, the detection limits were 0.002-0.010 mg·kg−1, and the limits of quantification (LOQ) were 0.005-0.025 mg·kg−1. At three spiked levels (LOQ, 2LOQ, and 5LOQ), the recoveries were in the range of 85.3%–113.2%, and the relative standard deviations were 1.5%–9.5% (n=6). Three target pesticides (chlormequat, cyromazine, and propamocarb) were detected in 57 samples of retail vegetables and fruits, and the residue of chlormequat in cowpea exceeded the maximum residue limit. Conclusion The established method of HILIC combined with ultra-performance liquid chromatography-tandem mass spectrometry and isotopic internal standard quantification has the characteristics of simplicity, stability, and easy operation, which is suitable for rapid screening and quantitative detection of selected eight high polar pesticide residues in large quantities of vegetables and fruits, and provides technical support for monitoring and risk assessment of high polar pesticide residues.
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OBJECTIVES@#To establish the ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method to detect ethanol metabolites phosphatidylethanol (PEth) in whole blood.@*METHODS@#An appropriate amount of aqueous solution including 1% formic acid was added to 100 μL whole blood, the protein was precipitated with acetone, centrifuged and the supernatant was purified and enriched by using Bond Elut Certify column. The eluent was redissolved with 1/1 isopropanol/acetonitrile (v/v) solution after nitrogen blowing and then tested by UPLC-MS/MS. Selective reaction monitoring scanning was carried out in negative ionization mode, and quantitative analysis was performed by external standard method.@*RESULTS@#PEth showed a linear relationship over the concentration range of 1-160 ng/mL in whole blood (r=0.999 9) with peak area. The detection limit was 0.2 ng/mL, the quantification limit was 1 ng/mL, the recovery rate was 97.43%-103.61%, the accuracy was 0.99%-1.77%, the intra-day precision was 0.4%-2.4%, and the inter-day precision was 1.1%-3.3%, and the matrix effect was 91.00%-99.55%. PEth was not detected in the in vitro blood samples supplemented with ethanol. PEth was detected positive in three drunk driving cases, and the concentration were 195.49, 83.67 and 876.12 ng/mL, respectively.@*CONCLUSIONS@#The established method has high sensitivity and specificity and the analysis results are accurate. It is suitable for the qualitative and quantitative analysis of PEth in whole blood.
Subject(s)
2-Propanol , Acetone , Acetonitriles , Biomarkers , Chromatography, High Pressure Liquid/methods , Chromatography, Liquid , Ethanol , Glycerophospholipids , Nitrogen , Tandem Mass Spectrometry/methodsABSTRACT
@#A deuterated internal standard quantitative analysis method based on liquid-liquid extraction-ultra performance liquid chromatography-tandem mass spectrometry (LLE-UPLC-MS/MS) for simultaneous determination of 10 illicit drugs in wastewater was established.Wastewater samples were concentrated by liquid-liquid extraction with dichloromethane: ethyl acetate (1∶1), and separated by a linear gradient of 0.1% formic acid-5 mmol/L ammonium formate aqueous solution and acetonitrile on a C18 column. The samples were then detected by ESI positive ion mode and multiple reaction monitoring mode (MRM) for quantitative analysis.All analytes had a good linear relationship (r ≥ 0.995 7) within the range of their respective standard curves; the limit of quantification was 1 ng/L (except amphetamine at 2.5 ng/L); the relative recovery rate ranged from 96.36% to 106.43%, and the intra- and inter-day precisions were less than 4.70%.This method is accurate, reliable and reproducible, and is suitable for the quantitative determination of 10 illicit drugs in wastewater.It is also suitable for wastewater with complex matrixes that affect solid phase extraction and enrichment.It provides a new analytical method for real-time monitoring of drug abuse.
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Objective:To compare the regulatory effects of <italic>Polygala tenuifolia</italic> and licorice-simmered <italic>P. tenuifolia</italic> on learning and memory， hypothalamus-pituitary-adrenal axis （HPA axis） function and neurotransmitters in rats with heart-kidney imbalance insomnia. Method:The rat model of insomnia induced by multi-factor stimulation was established. After the model being made， the administration groups were given the extracts of <italic>P. tenuifolia</italic> and licorice-simmered <italic>P. tenuifolia</italic> by gavage （dose of 8 g·kg<sup>-1</sup>·d<sup>-1</sup>）， while the normal group and model group were given the same volume of normal saline for 7 days. Morris water maze was used to detect the changes of learning and memory ability of rats in each group. Enzyme-linked immunosorbent assay （ELISA） was used to determine the levels of corticotropin-releasing hormone （CRH）， adrenocorticotropic hormone （ACTH） and cortisol （CORT） in serum of rats from each group. The contents of 5-hydroxytryptamine （5-HT）， dopamine （DA）， <italic>γ</italic>-aminobutyric acid （GABA） and glutamic acid （Glu） in the hypothalamus of rats were determined simultaneously by ultra performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS）. Result:Compared with the normal group， the spatial learning and memory ability of rats in the model group<italic> </italic>was decreased， the times and time of staying in target quadrant were significantly reduced （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， the levels of CORT， CRH and ACTH in serum were significantly increased （<italic>P<</italic>0.01）， the contents of GABA， DA， 5-HT in hypothalamus tissue were significantly decreased （<italic>P<</italic>0.01）， and the content of Glu was significantly increased （<italic>P<</italic>0.01）. Compared with the model group， the spatial learning and memory ability of rats in the <italic>P. tenuifolia</italic> group and licorice-simmered <italic>P. tenuifolia </italic>group<italic> </italic>were increased， the times and time of staying in the target quadrant were significantly increased （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， the levels of CORT， CRH and ACTH in serum were significantly decreased （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， the contents of GABA， DA and 5-HT in hypothalamus tissue were significantly increased （<italic>P<</italic>0.05， <italic>P<</italic>0.01）， and the content of Glu was significantly decreased （<italic>P<</italic>0.05）. The recovery degree of each index in the licorice-simmered <italic>P. tenuifolia</italic> group was better than that in the <italic>P. tenuifolia</italic> group. Conclusion:Both <italic>P. tenuifolia</italic> and licorice-simmered <italic>P. tenuifolia</italic> can improve the learning and memory ability， improve the function of HPA axis， regulate the level of central neurotransmitters， and have the effect of calming the mind and improving the intelligence of rats with heart-kidney imbalance insomnia. The effect of licorice-simmered <italic>P. tenuifolia</italic> is better than that of <italic>P. tenuifolia.</italic>
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Objective:To establish a method for the determination of artemisinin and arteannuin B in different <italic>Artemisia annua</italic> germplasms， compare the differences of the two compounds among different <italic>A. annua</italic> germplasm under the condition of hydroponic homogenization and explore the key factors affecting contents of principal compounds in different<italic> A. annua</italic> germplasms. Method:Seedlings from different <italic>A. annua</italic> germplasms were arranged randomly and fed in a hydroponic cultivation system. Contents of artemisinin and arteannuin B were detected by ultra performance liquid chromatography tandem mass spectrometry （UPLC-MS/MS） with multi-reaction monitoring mode and ACQUITY UPLC<sup>®</sup> BEH C<sub>18</sub> column （2.1 mm×100 mm， 1.7 μm）， mobile phase was water-acetonitrile （95∶5， containing 0.1% formic acid， A） and acetonitrile-water （95∶5， containing 0.1% formic acid， B） for gradient elution （0-3.5 min， 25%-1%A； 3.5-3.6 min， 1%-25%A； 3.6-5.0 min， 25%A）， the flow rate was set at 0.4 mL·min<sup>-1</sup>. The content differences of artemisinin and arteannuin B in different provenances of <italic>A. annua</italic> were detected and analyzed statistically. Result:The established method had high sensitivity and good separation. A significant difference of artemisinin and arteannuin B contents was observed in different germplasms under the same culture conditions， that is， under the constant temperature of 25 ℃ in hydroponics. The provenance with higher artemisinin content was Yunnan， and the content was 3 810.597 μg·g<sup>-1</sup>. The highest strain of arteannuin B was Shanxi provenance germplasm with the content of 1 691.747 μg·g<sup>-1</sup>. According to the content of artemisinin， the provenances were arranged as follows：Yunnan， Hainan， Hubei， Guangxi， Zhejiang， Shanxi， Beijing， Shandong， Heilongjiang， and Gansu province germplasms. Correlation analysis showed that there was a significant negative correlation between artemisinin content and latitude of <italic>A. annua</italic>， but there was no significant correlation between contents of artemisinin and arteannuin B and longitude. Conclusion:The contents of artemisinin and arteannuin B among different <italic>A. annua</italic> germplasms were significantly different under the same culture environment， and the dominant factors affecting biosynthesis and accumulation of artemisinin and arteannuin B in <italic>A. annua</italic> may be the genetic background， suggesting that germplasm improvement is the key factor to improve the medicinal quality of <italic>A. annua</italic> in subsequent cultivation.
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Objective:To establish an ultra-performance liquid chromatography-mass spectrometry （UPLC-MS/MS） for determining the plasma concentrations of 10 active ingredients in Wujiwan at different time points after oral administration， and to compare the pharmacokinetic characteristics between normal rats and rats with chronic visceral hypersensitive irritable bowel syndrome （CVH-IBS）. Method:CVH-IBS rat model was prepared by the neonatal rat colon percutaneous transluminal coronary angioplasty （PTCA） balloon stimulation method. After intragastric administration of Wujiwan （0.245 g·kg<sup>-1</sup>）， blood was collected from the jugular vein at different time points， and the plasma concentrations of 10 active ingredients （berberine hydrochloride， palmatine hydrochloride， coptisine hydrochloride， jatrorrhizine hydrochloride， epiberberine， dihydroberberine， evodiamine， evodine， paeoniflorin， albiflorin） in Wujiwan was detected simultaneously by UPLC-MS/MS， the pharmacokinetic parameters of each component in normal rats and CVH-IBS rats were calculated. Result:The established UPLC-MS/MS could sensitively and accurately detect the plasma concentrations of 10 active ingredients of Wujiwan in rats. Compared with the normal group， the absorption rates of these 10 active ingredients of Wujiwan in the blood of CVH-IBS rats all decreased to a certain extent， and the peak time （<italic>t</italic><sub>max</sub>） was prolonged. Among them， the <italic>t</italic><sub>max</sub> of berberine hydrochloride and jatrorrhizine hydrochloride were significantly prolonged from 54 minute and 39 minute to 90 minute， respectively （<italic>P</italic><0.05， <italic>P</italic><0.01）. Area under the plasma concentration-time curve （AUC<sub>0-</sub><italic><sub>t</sub></italic>） of each component increased， and evodiamine and paeoniflorin were significantly different （<italic>P</italic><0.05，<italic> P</italic><0.01）. The clearance rates （CL/<italic>F</italic>） of these 10 active ingredients were all decreased， among which berberine hydrochloride， palmatine hydrochloride and evodiamine had significant differences （<italic>P</italic><0.05， <italic>P</italic><0.01）. Conclusion:There are significant differences in the pharmacokinetic behavior of the active ingredients in Wujiwan between normal rats and CVH-IBS rats， which may be related to the destruction of microstructure of intestinal epithelial cells and the change of activity of liver enzymes under the pathological state of IBS.
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Objective:To establish ultra-performance liquid chromatography-tandem mass spectrometry （UPLC-MS/MS） for simultaneous determination of six hepatotoxic pyrrolizidine alkaloids in Verbenae Herba， and to carry out preliminary risk assessment according to the research results. Method:An ACQUITY UPLC HSS T3 column （2.1 mm×100 mm， 1.8 μm） was used for analysis with 0.05% formic acid and 2.5 mmol·L<sup>-1</sup> ammonium formate in water （A）-0.05% formic acid and 2.5 mmol·L<sup>-1</sup> ammonium formate in acetonitrile （B） as mobile phase for gradient elution （0-12 min， 3%-8%B； 12-25 min， 8%-15%B； 25-26 min， 15%-3%B； 26-30 min， 3%B）， the flow rate was 0.3 mL·min<sup>-1</sup>， the column temperature was 40 ℃， and the injection volume was 1 μL. MS system was operated by electrospray ionization （ESI） in the positive ion mode with multiple reaction monitoring mode. MS parameters of triple quadrupole and six analytes were optimized for qualitative and quantitative analysis. According to the determination results， the risk assessment was carried out by using margin of exposure （MOE） combined with transfer rate of hot water extraction. Result:Based on the instrument precision， linear range， repeatability， stability， recovery and other methodological validations， the results were in conformity with relevant standards of quantitative analysis. The linear ranges of intermedine， lycopsamine， intermedine <italic>N</italic>-oxide， lycopsamine<italic> N</italic>-oxide， echimidine<italic> N</italic>-oxide and echimidine were good （<italic>r</italic>≥0.999 0） between peak area and mass concentration in the ranges of 0.984-49.20， 0.994-49.70， 1.012-50.60， 1.032-51.60， 1.004-50.20， 1.016-50.80 µg·L<sup>-1</sup>， respectively. The average recoveries of these six analytes were 87.2%-94.2% with relative standard deviation （RSD）<4.0%. Their MOE values were >10 000. Conclusion:The UPLC-MS/MS established in this study is stable and feasible， which can provide scientific basis for the quality control and safety evaluation of hepatotoxic pyrrolizidine alkaloids in Verbenae Herba.
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OBJECTIVE: To establish a highly sensitive and selective ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of the concentrations of lamotrigine, olanzapine and quetiapine in human plasma to provide guidance for clinical drug use. METHODS: The plasma samples were precipitated by methanol, voriconazole was used as internal standard, and then gradiently eluted by ACQUITY UPLC BEH C18 column (2.1 mm×50 mm, 1.7 μm) using mobile phase consisting of 0.1% formic acid solution and methanol. Multiple reaction monitoring (MRM) was conducted in ion detection mode using positive electrospray ionization source. RESULTS: The linear ranges of the calibration curves for lamotrigine, olanzapine and quetiapine in human plasma were 0.5-20 μg•mL-1, 2-200 and 10-1 000 ng•mL-1, respectively. The method had good matrix effect, extraction recovery, accuracy, precision and stability, and was successfully applied to analyze plasma samples of 45 patients. CONCLUSION: The UPLC-MS/MS method for determination of lamotrigine, olanzapine and quetiapine is proven to be a sensitive and reliable protocol for clinical therapeutic drug monitoring.
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Objective To establish an assay method for unbound teicoplanin in plasma by centrifugal ultrafiltration combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Methods Protein was removed from plasma by a Centrifree® ultrafiltration device. The ultrafiltrate was injected to determine the unbound concentration of teicoplanin. EndeadvorsilTM C18 column (1.8 μm, 50 mm×2.1 mm) was used with gradient elution of acetonitrile and 0.02 mol/L ammonium acetate solution (containing 0.1% formic acid). The detection was performed on a triple-quadrupole tandem mass spectrometer by multiple reaction monitoring (MRM)mode via electro spray ionization (ESI). Results The calibration curve of unbound teicoplanin in plasma was linear over the range of 0.10 to 8.00 μg/ml (r=0.999). The intra-assay precision and the inter-assay precision of samples didn't exceed 7.00%. The average relative recovery ratio was 97.9%, and the matrix effect factor was 0.97. The samples had good stability after being stored at room temperature for 10 h or at −20 ℃ for 15 days, and freeze-thawed 3 times (RSDs were all within 6.50%). Conclusion This method is convenient, fast, sensitive and accurate. It provided a basis for clinical development of teicoplanin unbound concentration monitoring.
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Objective@#To develop the ultra performance liquid chromatography tandem mass spectrometry ( UPLC-MS/MS ) for the determination of perfluorocarboxylic acids ( PFCAs ) in fish.@*Methods@#The fish samples were extracted with tert-butyl methyl ether and purified by WAX columns. The WAX cartridges were rinsed with methanol and 25 mmol/L ammonium acetate, and the target compound residues were eluted with 0.5% ammonia methanol and then redissolved with 50% methanol aqueous solution after nitrogen blowing to nearly dry. Nine kinds of PFCAs were simultaneously quantified by UPLC-MS/MS with 1 mmol/L ammonium acetate-methanol solution as the mobile phase.@*Results@#The extraction was separated well in UPLC BEH C18 column. There were good linear correlations of nine kinds of PFCAs in the range of 1.0-200.0 ng/mL, with the coefficients all more than 0.99. The limits of detection and quantification were 0.06-0.19 μg/kg and 0.19-0.62 μg/kg, respectively. The recovery rates were 70.08%-117.24% at different spiked levels ( 5.0, 25.0, 50.0 μg/kg ), and the relative standard deviations were 2.31%-19.68%. @*Conclusion@#Through optimizing the pretreatment conditions, the mobile phase of liquid chromatography and the detection conditions of mass spectrometry, the UPLC-MS/MS could meet the monitoring requirements of PFCAs in fish.
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Objective:To investigate the pharmacodynamics effects of antiobesity, lipid-lowering and the regulations of serum bile acid profiles of Lidan Ruanjian prescription (LDRJ) in obesity rats induced by high-fat diet. Method:The 42 rats were fed high-fat diet for 9 weeks to establish model of obese rats，24 rats were randomly divided into model group, high and low-dose LDRJ group (30,15 g·kg-1). Another 8 normal rats were selected as the normal group.The model group and normal group were given normal saline, and drug group was given the corresponding dose of drug for 4 weeks. Body weight, liver weight, white adipose tissue (WAT) weight were determined after administration medicine for 4 weeks. The bile flow of the rats was measured by bile duct intubation and fasting serum lipid levels of total cholesterol (TC), total triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C) were detected by automatic biochemical analyzer. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) assay was used to test serum bile acid profile of each group rats. Result:Compared with the control group, the average body weight, liver weight, WAT weight of the model group were significantly increased (P<0.01), while the fasting serum TC, TG and LDL-C levels were elevated (P<0.05，P<0.01). The total bile secretion and bile flow at each test point within 2 h were decreased and the proportion of primary bile acids was decreased (P<0.05).The serum total bile acid content decreased significantly（P<0.01），levels of cholic acid (CA), deoxycholic acid (DCA), chenodeoxycholic acid (CDCA), hyodeoxycholic acid (HDCA), taurocholic acid (TCA), taurodeoxycholic acid (TDCA), taurochenodeoxycholic acid (TCDCA), taurohyodeoxycholic acid (THDCA) and glycodeoxycholic acid (GDCA) were significantly reduced (P<0.05，P<0.01). Compare with model group, body weight, liver weight in high and low-dose LDRJ groups reduced significantly(P<0.05，P<0.01). Fasting serum TC, TG and LDL-C levels were decreased in high-dose group(P<0.05，P<0.01), so did as TG levels in low-dose group(P<0.05). The bile flow rate increased significantly in high-dose group 1~1.5 h after administration (P<0.05). All dose treatment groups increased the proportion of primary bile acids (P<0.05) and changed the bile acid profile, especially elevated the bile acid levels of TCA, DCA, glycocholic acid (GCA), GDCA in high-dose LDRJ group (P<0.05，P<0.01), while TCA and TCDCA in low-dose group (P<0.05). Conclusion:LDRJ has significant lipid-lowering and antiobesity effects and the mechanism might involve the increase of bile secretion, the stimulation of primary bile acid synthesis and the regulation of bile acid profile.
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@#A quantitative analysis method based on solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) for simultaneous determination of illicit drugs and their metabolites in wastewater was established. Samples filtered at pH of 2 and spiked with internal standard were loaded to Oasis Prime MCX cartridges for solid-phase extraction. The samples were washed with 4 mL of methanol and eluted with 4 mL of 5% ammonia in acetonitrile before reconstituting with 0.1% formic acid/water solution. ZORBAX Eclipse Plus C18 column was used for chromatography, and gradient elution was performed with 0.1% formic acid/water solution and acetonitrile as mobile phase. The samples were then detected by electrospray ionization (ESI) in positive ion mode, and multiple reaction monitoring mode (MRM) was adopted for quantitative analysis. All analytes had a good linear relationship (r ≥ 0.993 2) within the range of their respective standard curve; the limit of quantification was 1 ng/L (except amphetamine at 2.5 ng/L); the extraction recovery ranged from 82.13% to 99.96%; and the intra- and inter-day precisions were less than 9.43%. The method is accurate, reliable and reproducible, and is suitable for the quantitative determination of illicit drugs and their metabolites in wastewater and can provide an analytical method for real-time monitoring of drug abuse.
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Objective To compare ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) and chemiluminescence immunoassay(CLIA) measurement of human serum androgen levels in polycystic ovarian syndrome(PCOS). Methods 160 PCOS patients and 146 healthy subjects(control group) were recruited and their serum androgen levels——measurements of testosterone and dehydcoepiandrosterone sulfate (DHEA-S) were tested by UPLC-MS/MS and CLIA. The androgen results combined with body mass index(BMI) were analyzed by ROC curve. According to area under curve(AUC) calculated by SPSS, a better method will be selected to provide accurate test results for physicians. Results (1)AUC of DHEA-S tested by UPLC-MS/MS was significantly higher than the one tested by CLIA(P<0.01). There was no significant difference between the AUC of T tested by UPLC-MS/MS and the one tested by CLIA. (2)AUC of T combined with DHEA-S tested by HPLC was not only significantly higher than the AUC of two combined indicators tested by CLIA(P<0.01),but also significantly higher than the AUC of a single indicator——either T(P<0.01) or DHEA-S(P<0.01) tested by UPLC-MS/MS. (3)The AUC of T,DHEA-S combined with BMI tested by HPLC was not only significantly higher than the AUC of three combined indicators tested by CLIA(P<0.01),but also higher than the AUC of two combined indicators tested by UPLC-MS/MS(P<0.05). Conclusion T and DHEA-S tested by UPLC-MS/MS combined with BMI has a certain reference value in the diagnosis of PCOS.
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An effective method was developed for determination of pyraclostrobin and BF 500-3 residues in pollen and honey of litchi by QuEChERS coupled with ultra performance liquid chromatography-tandem mass spectrometry. The samples were extracted by acetonitrile and cleaned by primary secondary amine(PSA) and C18. In the positive ion mode and multi reaction monitoring mode,the analytes were quantified by the matrix matching standard solutions, and the pretreatment and mass spectrometry conditions were evaluated. The matrix matched standard solutions of pyraclostrobin and its metabolite BF 500-3 showed good linearities in the concentration range of 1-100 μg/L, with the correlation coefficients (R2) of 0.991-0.999. The average recoveries were 87.0%-97.8% with relative standard deviations of 1.3%-3.7%. The limit of detection (LOD) and the limit of quantification(LOQ) were 0.08-0.20 μg/kg and 0.20-0.50 μg/kg,respectively. The method was easy, quick and highly sensitive, and was suitable for quick determination of pyraclotrobin and its metabolites in pollen and honey of litchi.
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A sensitive method was proposed for determination of 13 kinds of sulfonylurea herbicides residues in aquatic products by solid phase extraction-ultra performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (SPE-UPLC-MS/MS). The edible part of carp, penaeus vannamei,crab,clam and sea cucumber were collected and homogenized. Analytes was extracted with ethyl acetate,and then cleaned up by MAX solid phase extraction column. Qualitation of the analytes was achieved with multiple reaction monitoring (MRM) and the external standard method was used for quantification. The 13 kinds of sulfonylurea herbicides showed good linearity in the concentration range of 5.0-100.0 μg/L respectively. The detection limits of the 13 analytes were 1.0 μg/kg, and the limit of quantification was 2.0 μg/kg. The average recoveries ranged from 75.4% to 118.3% with relative standard deviations from 2.1% to 14.5%. The 13 target analytes were not detected in grass carp,carp,sea cucumber,prawn,turbot of breeding and crabs from the market. The halosulfuron-methyl was detected in the edible tissues of crabs exposed to a 1.0 mg/L halosulfuron-methyl solution for 24,48 and 72 h,and the concentrations were 6.20, 12.1 and 16. 6 μg/kg respectively. The method can be stable and sensitive, and is applied to the determination of 13 kinds of sulfonylurea herbicides residues in aquatic products.
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An analytical method based on ultra performance liquid chromatography-tandem mass spectrometry was developed for the determination of SIOC0426 residues in environment samples ( soil, sediment and water) . The fate of SIOC0426 in three kinds of soils was also evaluated. The target compound was extracted with acetonitrile, cleaned up by C18 cartridge, and analyzed by gradient ultra performance liquid chromatography-tandem mass spectrometry with electrospray ionization under positive mode ( ESI+) using a UPLC BEH C18 column. The method was validated using fortified soil, sediment and water. Mean recoveries of SIOC0426 at three spiked levels ( 0 . 005 , 0 . 05 and 2 . 0 mg/kg ) ranged from 87% to 106% with relative standard deviations of 2. 8%-8. 0%. Limits of quantification ( LOQs) of SIOC0426 in soil ( sediment) and water were 0. 2 μg/kg and 0. 2 μg/L, respectively. Linear calibration functions with correlation coefficients R2>0. 9999 were obtained in the concentration range of 0. 5-20 μg/L. This method was applied to the analysis of SIOC0426 residues in soil degradation samples. The results showed that the half-life of SIOC0426 ranged from 1. 72 days to 28. 2 days in three kinds of soils under aerobiotic conditions. While, the half-life of SIOC0426 ranged from 2. 93 days to 31. 4 days in three kinds of soils under anaerobic conditions. The degradation speed of SIOC0426 under aerobiotic conditions was faster than that under anaerobic conditions in the same soil. And the degradation speed of SIOC0426 in soils may be connected with the pH value of soils, cation exchange capacity and soil texture.
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Objective: To develop an ultra-performance liquid chromatography-tandem mass spectrometry ( UPLC - MS/MS ) method for the determination of nine fat-soluble vitamins in health foods. Methods:The samples were extracted by ultrasonic in organic solvents followed by the separation on a Waters ACQUITY UPLC BEH C18 column(100 mm × 2. 1 mm, 1. 7 μm) with gradient elution of 0. 1% formic acid in methanol and 0. 1% formic acid solution as the mobile phase and in a mode of atmosphere pressure chemical i-onization multiple reaction monitoring (MRM). Results:The method exhibited a good linear relationship (r≥0. 99) with the detection limit between 0. 9 and 38. 3μg/100 g for the nine fat-soluble vitamins. The recoveries were 78. 5%-114. 9% and the RSDs were 1. 57%-11. 1%(n=6). Conclusion:The analytical method is simple, rapid, accurate and sensitive, and suitable for the determina-tion of fat-soluble vitamins in nutritional supplements.
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An analytical method based on ultra performance liquid chromatography-tandem mass spectrometry was developed for the determination of SIOC0426 residues in environment samples ( soil, sediment and water) . The fate of SIOC0426 in three kinds of soils was also evaluated. The target compound was extracted with acetonitrile, cleaned up by C18 cartridge, and analyzed by gradient ultra performance liquid chromatography-tandem mass spectrometry with electrospray ionization under positive mode ( ESI+) using a UPLC BEH C18 column. The method was validated using fortified soil, sediment and water. Mean recoveries of SIOC0426 at three spiked levels ( 0 . 005 , 0 . 05 and 2 . 0 mg/kg ) ranged from 87% to 106% with relative standard deviations of 2. 8%-8. 0%. Limits of quantification ( LOQs) of SIOC0426 in soil ( sediment) and water were 0. 2 μg/kg and 0. 2 μg/L, respectively. Linear calibration functions with correlation coefficients R2>0. 9999 were obtained in the concentration range of 0. 5-20 μg/L. This method was applied to the analysis of SIOC0426 residues in soil degradation samples. The results showed that the half-life of SIOC0426 ranged from 1. 72 days to 28. 2 days in three kinds of soils under aerobiotic conditions. While, the half-life of SIOC0426 ranged from 2. 93 days to 31. 4 days in three kinds of soils under anaerobic conditions. The degradation speed of SIOC0426 under aerobiotic conditions was faster than that under anaerobic conditions in the same soil. And the degradation speed of SIOC0426 in soils may be connected with the pH value of soils, cation exchange capacity and soil texture.
ABSTRACT
A sensitive and effective method for determination of 16 kinds of antibiotics, including tetracycline, sulfonamide, fluoroquinolone and macrolide, in livestock and poultry manure using solid phase extraction-ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established.Aiming at the chemical properties and sample impurities of the target, the parameters such as mass spectrum conditions, types of extraction and ultrasonic power were optimized.Finally, the samples were extracted with 50% acetonitrile in phosphate buffer solution (pH =4) for three times, followed by ultrasonic steaming, centrifugal and rotary, dilution, and purified by SAX-HLB.After sample loading, the solid phase was washed with 10 mL of methanol-acetone (80∶20, V/V), evaporated to near dryness at 35℃, and then re-dissolved and vortex mixed in 1 mL of 0.1% formic acid∶methanol (1∶1, V/V).The extracts were analyzed with UPLC-MS/MS and calculated by external standard method based on the monitored product ion.The results indicated that the average spiked recoveries of tetracycline, sulfonamide, fluoroquinolone and macrolide in manure were 56.4%-94.6% with relative standard deviations (RSDs) of 2.6%-19.8%, the LODs (S/N=3) were 0.01-2.50 μg/kg, and the LOQs (S/N=10) were 0.05-7.90 μg/kg.The method was simple with high stability, high sensitivity and good reproducibility, and suitable for the simultaneously determination of many antibiotics in animal and poultry manure.
ABSTRACT
Objective To optimize the particle size of Huoxue powder by contents comparison of emodin,phellodendrine,berberine and jatrorrhizine before and after permeabilized skin absorption of Huoxue powder in different particle size of 0.150,0.075,0.048,0.038 mm.Methods The contents of emodin,phellodendrine,berberine and jatrorrhizine in transparent absorbent fluid of Huoxue power in different particle size within 24 hours were measured by ultra performance liquid chromatography tandem mass spectrometry,and optimize its particle size by contents comparison of the effective components.Results The contents of the active components in Huoxue power with the particle size of 0.075 mm were high before and after percutaneous absorption.Conclusion Particle size of 0.075 mm is best for Huoxue powder.