Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC...Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.展开更多
为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪...为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。展开更多
为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶...为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶液20 m L,涡旋1 min,超声10 min,离心8 min。上清液于45℃旋蒸至近干,加入2.00 m L 70%(体积分数)乙腈溶液涡旋溶解残留物,再加入200 mg C18涡旋振荡30 s,离心5 min。收集上清液,过0.22μm有机滤膜,滤液采用高效液相色谱-串联质谱法测定。在色谱分析中,以Waters Atiantis^(TM) d C_(18)色谱柱为固定相,水-乙腈体系为流动相进行梯度洗脱;在质谱分析中,以电喷雾离子源负离子(ESI-)模式电离,选择反应监测(SRM)模式检测,内标法定量。结果显示,氯硝柳胺的质量浓度在0.20~50.00μg·L^(-1)内和其定量离子峰面积与同位素内标定量离子峰面积的比值呈线性关系,检出限(3S/N)为0.2μg·kg^(-1)。按照标准加入法进行回收试验,回收率为92.1%~113%,测定值的相对标准偏差(n=6)为1.6%~5.9%。方法用于实际样品的分析,检出的氯硝柳胺的质量分数为0.580~2.18 mg·kg^(-1)。展开更多
文摘Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.
文摘为建立一种可同时检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法,试验采用正己烷去脂,联合QuEChERS净化结合冷冻脂质过滤法,建立检测鸽蛋中5类24种兽药残留的高效液相色谱-串联质谱法。样品中的5类兽药(氯霉素类、磺胺类、硝基咪唑类、喹诺酮类和抗病毒类)经1.0%乙酸乙腈溶液提取,氮气吹干,冷冻过夜后,结合QuEChERS净化和正己烷去脂,采用1 mL 0.1%甲酸水-乙腈溶液(v/v,90∶10)复溶;高效液相色谱-串联质谱测定,内标法定量,采用实际样品建立方法的初步应用。结果显示:24种兽药在2.0~200 ng/mL线性关系良好(R2>0.99),该方法的定量限为2μg/kg,平均回收率为62.2%~117.1%,相对标准偏差4.3%~18.9%;实际样品检出的7种目标化合物与标准方法相比的相对标准偏差为1.34%~5.20%。研究表明,建立的检测鸽蛋中多类兽药残留的高通量液相色谱-串联质谱法省去固相萃取步骤,成本较低,灵敏高效,回收率优良、重复性稳定,适用于鸽蛋中多类兽药的快速监测分析。
文摘为简化前处理过程,降低方法的检出限,进行了题示研究。采集鱼塘底泥样品,混匀、缩分、冷冻干燥、除杂、研磨、过筛后混匀,分取5.00 g,加入10.0μg·L^(-1)^(13)C_(6)-氯硝柳胺水合物标准溶液0.2 m L和含2.0%(体积分数)氨水的乙腈溶液20 m L,涡旋1 min,超声10 min,离心8 min。上清液于45℃旋蒸至近干,加入2.00 m L 70%(体积分数)乙腈溶液涡旋溶解残留物,再加入200 mg C18涡旋振荡30 s,离心5 min。收集上清液,过0.22μm有机滤膜,滤液采用高效液相色谱-串联质谱法测定。在色谱分析中,以Waters Atiantis^(TM) d C_(18)色谱柱为固定相,水-乙腈体系为流动相进行梯度洗脱;在质谱分析中,以电喷雾离子源负离子(ESI-)模式电离,选择反应监测(SRM)模式检测,内标法定量。结果显示,氯硝柳胺的质量浓度在0.20~50.00μg·L^(-1)内和其定量离子峰面积与同位素内标定量离子峰面积的比值呈线性关系,检出限(3S/N)为0.2μg·kg^(-1)。按照标准加入法进行回收试验,回收率为92.1%~113%,测定值的相对标准偏差(n=6)为1.6%~5.9%。方法用于实际样品的分析,检出的氯硝柳胺的质量分数为0.580~2.18 mg·kg^(-1)。
