QuEChERS-高效液相色谱-串联质谱法测定水稻中二氯喹啉酸及其代谢物的残留

Determination of Quinclorac and Its Metabolites in Rice Based on QuEChERS-Liquid Chromatography-Tandem Massspectrometry

[目的]建立水稻中二氯喹啉酸及其代谢物二氯喹啉酸甲酯残留的QuEChERS-HPLC-MS/MS分析方法,将该方法运用到不同地区水稻样品的检测。[方法]二氯喹啉酸和二氯喹啉酸甲酯分别经甲醇和乙腈提取,C18、PSA和GCB净化,C18色谱柱分离,电喷雾离子源(ESI+),多反应监测模式(MRM)下分析。[结果 ]在0.05、0.1、1 mg/kg质量分数添加水平下,二氯喹啉酸平均添加回收率为83%~96%,RSD为0.4%~8.7%。在0.01、0.1、1 mg/kg添加水平下,二氯喹啉酸甲酯平均添加回收率为79%~106%,RSD为0.2%~14.4%。[结论]通过检测1年12地的水稻样品,二氯喹啉酸在水稻中的残留量为0.05~0.48 mg/kg,二氯喹啉酸甲酯的残留量均小于0.01 mg/kg,低于国家标准中规定的二氯喹啉酸在水稻上的最大残留限量(1 mg/kg)。该方法简单快速准确,适合于水稻中二氯喹啉酸及其代谢物二氯喹啉酸甲酯的残留检测。

[Aims] This study aims to establish a QuEChERS-HPLC-MS/MS method for the determination of quinclorac and its metabolite quinclorac methyl ester in rice, and to be applied for the determination of rice samples in different regions. [Methods] The quinclorac and quinclorac methyl ester in rice were extracted by methanol and acetonitrile, purified by C18, PSA and GCB. It was determined by electrospray ionization(ESI) positive ion multiple reaction monitoring mode(MRM). [Results] At three spiked levels(0.05, 0.1 and 1 mg/kg) of quincloracin rice(brown rice, rice husk and straw), the average recoveries of quinclorac ranged from 83 to 96%, and the relative standard deviation(RSDs) ranged from 0.4 to 8.7%. At three spiked levels(0.01, 0.1 and 1 mg/kg) of quinclorac methyl ester, the average recoveries of quinclorac ranged from 79 to 106%, and the RSDs ranged from 0.2 to 14.4%. [Conclusions] The residues of quinclorac and quinclorac methyl ester were 0.05-0.48 mg/kg and 0.01 mg/kg, respectively, which were lower than the maximum residue limit of quinclorac in rice of China National Standard(1 mg/kg). The method is simple,rapid and accurate, and is suitable for the determination of quinclorac and its metabolite methyl in rice.