A multi-residue method based on high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was developed for the quantitative determination of abamectin,ivermectin and emamectin benzoate in grouper plasma,muscle and liver.The target analytes were extracted with acetonitrile and then cleaned up with an alkaline alumina column/LC-C18 SPE column.The analytes were separated on a Thermo Hypersil Gold C18 column by gradient elution with 0.1％ formic acid-10 mmol/L ammonium acetate as mobile phase A and acetonitrile as mobile phase B,and detected by multiple reaction monitoring (MRM) with electrospray ionization (ESI) under positive ion mode.The target compounds were quantified by the matrix-matched external standard method.Both pesticides could move into water through various environmental routes.Therefore,the bioaccumulation and elimination of avermectin and ivermectin in groupers were studied by bath administration at the upper and lower concentration limits (4 and 8 ng/mL for avermectin,and 6 and 12 ng/mL for ivermectin) in environmental water.Meanwhile,the food safety risk of the pesticide residues in fish was assessed.The results showed that the calibration curves were linear (R2＞ 0.99) in the concentration range of 2.5-200 ng/mL for abamectin and ivermectin and 0.25-20 ng/mL for emamectin benzoate.The limits of detection (LOD) for abamectin,ivermectin and emamectin benzoate were 2.5,2.5 and 0.25 ng/mL in plasma,1,1 and 0.1 μg/kg in muscle,2.5,2.5 and 0.25 μg/kg in liver,respectively.The limits of quantification (LOQ) were 5,5 and 0.5 ng/mL in plasma,2,2 and 0.2 μg/kg in muscle,5,5 and 0.5 μg/kg in liver,respectively.The average recoveries at three spiked levels ranged from 74.6％ to 93.6％.Intra-day and inter-day relative standard deviations (RSDs) were 2.3％-10.9％ and 9.2％-12.6％,respectively.Abamectin and ivermectin were no-bioaccumulative substances and their elimination processes in grouper conformed to a first order kinetics equation.Under the conditions of this study,drug concentration was an important factor affecting the residual drug concentration and elimination time in grouper muscle tissues.Gouper was safe for consumption 22 and 39 days after 72 h bath administration for 4-8 ng/mL abamectin and 6-12 ng/mL ivermectin,respectively.%建立高效液相色谱-串联质谱同时定量检测石斑鱼血浆、肌肉组织、肝脏组织中阿维菌素、伊维菌素、甲氨基阿维菌素苯甲酸盐方法.样品经乙腈提取,碱性氧化铝固相萃取柱和LC-C1s固相萃取柱串联净化,Thermo Hypersil Gold C18色谱柱分离,10 mmol/L乙酸铵-0.1％甲酸溶液和乙腈梯度洗脱,电喷雾正离子模式下以多反应监测方式检测,基质匹配法外标定量.分别以环境水体中阿维菌素上下限质量浓度(4、8 ng/mL)、伊维菌素上下限质量浓度(6、12 ng/mL)作为受试质量浓度开展生物富集、消除实验,并对石斑鱼的食用安全进行了风险评估.结果表明,阿维菌素和伊维菌素在2.5～200 ng/mL范围内,甲氨基阿维菌素苯甲酸盐在0.25～20 ng/mL范围内,线性回归系数均大于0.99.方法检出限分别为2.5、2.5、0.25 ng/mL(血浆),1、1、0.1μg/kg(肌肉组织),2.5、2.5、0.25 μg/kg(肝脏组织),方法定量限分别为5、5、0.5 ng/mL(血浆),2、2、0.2 μg/kg(肌肉组织),5、5、0.5 μg/kg(肝脏组织).3个添加量的平均回收率为74.6％～93.6％,日内相对标准偏差为2.3％～10.9％,日间相对标准偏差为9.2％～12.6％.阿维菌素、伊维菌素均属于非生物累积性物质,在石斑鱼体内代谢规律相同,均按一级动力学过程从体内消除.本研究条件下,环境水体中药物质量浓度是石斑鱼肌肉组织中药物残留质量浓度及消除时间的重要因素.为保证食用安全,环境水体中阿维菌素质量浓度达到4～8 ng/mL时,石斑鱼浸浴72 h后安全食用时间为22 d;环境水体中伊维菌素质量浓度达到6～12 ng/mL时,石斑鱼浸浴72 h后安全食用时间为39 d.
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