高效液相色谱-串联质谱法测定稻渔土壤中氟虫腈及其代谢物残留

建立了高效液相色谱-串联质谱（HPLC-MS/MS）法测定稻渔土壤中氟虫腈及其代谢物残留。样品经乙腈恒温振荡提取，ENVI-18固相萃取柱和10 mg GCB净化，ZORBAX Extend-C18色谱柱（2.1 mm×100 mm×1.8 μm）分离，电喷雾负离子模式检测，基质匹配标准曲线外标法定量。结果表明，稻渔土壤中氟虫腈、氟甲腈、氟虫腈砜和氟虫腈亚砜的平均回收率在83.5%~110.3%之间，相对标准偏差在1.9%~11.5%之间，氟虫腈及其代谢物在0.5~100 μg/L浓度范围内的线性关系良好，相关系数均大于0.998，检出限和定量限分别为1.0、3.0 μg/kg。该方法操作简单、结果准确、可靠，可实现样品的批量化处理，能够满足稻田水产品中氟虫腈及其代谢物检测的需求。

Determination of Fipronil and Its Metabolites in Paddy-fish Soil Using High Performance Liquid Chromatography-Tandem Mass Spectrometry

Residues of fipronil and its metabolites in paddy-fish soil were detected using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Samples were extracted with oscillation and acetonitrile in constant temperature, and subsequently purified by solid phase extraction using ENVI-18 column and 10 mg GCB. The target compounds were separated on an Agilent ZORBAX Extend-C18 column (2.1 mm×100 mm×1.8 μm), and determined using electrospray ionization (ESI) source at negative mode with multiple reation monitoring (MRM). The analytes were quantified with external standard using the matrix-matched standard calibration curve method. The results indicated that the average spiked recoveries of fipronil, fipronil-desulfinyl, fipronil-sulfone and fipronil-sulfide in paddy-fish soil were 83.5%-110.3% with the relative standard deviations (RSDs) of 1.9%-11.5%. Good linearities were obtained in the range of 0.5-100 μg/L, and the correlation coefficients were greater than 0.998, the limits of detection (LODs) were 1.0 μg/kg, and the limits of quantification (LOQs) were 3.0 μg/kg. This method is simple, accurate and reliable, which can meet the detection requirements of fipronil and its metabolites in paddy-fish soil.