噁唑酰草胺及其代谢物在水稻上的残留检测方法和储藏稳定性研究

Study on the Residue Determination and Storage Stability of Metamifop and Its Metabolites in Rice

建立了水稻糙米、稻壳和稻杆中噁唑酰草胺及代谢物HPMFPA、HFMPA、6-CBO的残留分析方法。采用乙腈为提取剂,PSA和C18为分散剂的QuEChERS前处理方法,用超高效液相色谱-三重四级杆质谱在选择离子监测(SIM)模式下进行检测,外标法定量。结果表明,噁唑酰草胺及代谢物在0.01~0.5 mg·kg^(-1)添加水平范围内,平均回收率为70.1%~108.8%,相对标准偏差为1.8%~11.9%。在储藏温度-18℃、储藏时间为32周的试验期间,噁唑酰草胺及其代谢物降解率均小于30%。该方法简单快捷,准确且灵敏度高,是一种较为实用的检测分析方法。储藏稳定性试验结果表明,噁唑酰草胺及其代谢物在水稻样品中均比较稳定。

A residual analysis method was established for the simultaneous determination of metamifop and its metabolites HPMFPA,HFMPA,6-CBO in brown rice,rice hull,rice stalk.The samples were extracted with acetonitrile,and then purified by QuEChERS with primary secondary amine(PSA)and C18 sorbent,and then determined by ultra performance liquid chromatography-triple quadrupole tandem mass spectrometry in select ion monitoring mode with external standard method for quantification.The results showed that the recoveries of metamifop and its metabolites at the addition levels(0.01~0.5 mg·kg^(-1))were within 70.1%~108.8%,with the relative standard deviation(RSD,n=5)between 1.8%and 11.9%.The degradation rate of both metamifop and its metabolites was less than 30%during 32 weeks of storage at-18℃.The method is simple,fast,accurate and sensitive,which can be used as a practical detection and analysis technique.The storage stability results showed that metamifop and its metabolites were stable in rice samples.