【摘要】 目的建立大米中异噁唑草酮及代谢物残留量的液相色谱-串联质谱法测定方法。方法试样中残留的异噁唑草酮除草剂及代谢物用乙酸乙腈溶液(1:99,V:V)高速匀浆提取,提取液经N-丙基乙二胺(PSA)、十八烷基硅烷(ODS)净化,经色谱柱为ACQUITY UPLC BEH Phenyl分离和流动相为1.5%乙酸的乙酸铵(1mmol/L)-乙腈进行梯度洗脱,用配有大气压化学电离源(APCI)的液相色谱-串联质谱仪检测和确证。结果异噁唑草酮及代谢物在0.0025~1.000μg/m L浓度范围内呈现良好线性关系(r=0.9998~0.9999)。当样品加标浓度在5~200μg/kg范围内时,其样品加标平均回收率为70.2%~110.6%,相对标准偏差为7.38%~12.84%。异噁唑草酮及代谢物的最低检出限分别为10μg/kg、5μg/kg。结论本方法适用于大米中异噁唑草酮及代谢物残留的同时测定。更多还原

【Abstract】 Objective To establish a novel method for determination of isoxaflutole and its metabolites residues in rice by liquid chromatography-mass spectrometry/mass spectrometry(LC-MS/MS). Methods With acetic acid acetonitrile solution(1:9,V:V) as the extraction, the test sample were extracted by means of high speed homogenization, cleaned up by primary secondary amine(PSA) and octadecylsilane(ODS). The residues in the extracts were separated on a reversed–phase liquid chromatography with ACQUITY UPLC BEH Phenyl column using a gradient elution program of 1.5% acetic acid(1 mmol/L) ammonium acetate solution and acetonitrile. The residues were determined and confirmed by LC-MS/MS equipped with atmosphere pressure chemical ionization source. Results The calibration curve of isoxaflutole and its metabolites showed a good linearity in the range of 0.0025~1.000 μg/m L with the correlation coefficient of 0.9998~0.9999. The average recoveries of isoxaflutole and its metabolites in spiked samples were in the range of 70.2%~110.6%, and the relative standard deviations(RSD) were between 7.38%~12.84% at spiked levels of 5~200 μg/kg. The limit of detection was 10 μg/kg and 5 μg/kg for the isoxaflutole and its metabolites, respectively. Conclusion This method can be used for the simultaneous determination of isoxaflutole and its metabolites residues in rice.更多还原