采用液相色谱-串联质谱法测定鸡蛋中氟虫腈及其3种代谢物的含量。鸡蛋样品经乙腈提取，离心后上清液用氮气吹至近干，残渣用水溶解后，经HLB固相萃取柱净化。以Shim-pack XR-ODS C₁₈色谱柱为分离柱，以不同体积比的4 mmol·L^-1乙酸铵溶液和甲醇的混合液为流动相进行梯度洗脱，采用电喷雾负离子源和多反应监测模式检测。氟虫腈及其3种代谢物的质量分数均在1~50 μg·kg^-1内与其对应的峰面积呈线性关系，检出限（3S/N）均为0.3 μg·kg^-1。在1，5，20 μg·kg^-1等3个浓度水平进行加标回收试验，回收率为89.9%~96.1%，测定值的相对标准偏差（n=6）为1.6%~3.3%。

LC-MS/MS was applied to the determination of fipronil and its 3 metabolites in eggs. The egg sample was extracted with acetonitrile. After centrifugation, the supernatant was evaporated to near dryness by N₂-blowing. The residue was taken up with water and then purified with HLB solid phase extraction column. Shim-pack XR-ODS C₁₈ chromatographic column was used as stationary phase, and the mixture of 4 mmol·L^-1 ammonium acetate solution and methanol mixed in different ratios was used as mobile phase in gradient elution. ESI^- and multi-reactions monitor mode were adopted in MS/MS. Linear relationships between values of peak area and mass fraction of fipronil and its 3 metabolites were kept in the same range of 1-50 μg·kg^-1, with same detection limit (3S/N) of 0.3 μg·kg^-1. Tests for recovery were made by standard addition method at the concentration levels of 1, 5, 20 μg·kg^-1, giving values of recovery and RSD's (n=6) in the ranges of 89.9%-96.1% and 1.6%-3.3% respectively.