果蔬中双甲脒残留量气质联用快速测定方法

A Rapid Determination Method for Amitraz Residues in Fruits and Vegetables by GC-MS/MS

通过优化前处理过程,建立快速测定果蔬中双甲脒及代谢物残留量的气质联用法。试样中的双甲脒在微波消解罐中经酸水解成2,4-二甲基苯胺,碱化后用正己烷萃取,用气质联用仪检测,以外标法定量。在本方法实验条件下,双甲脒水解产物在5~2 000 ng/mL范围内其测定响应与质量浓度呈现良好的线性关系,线性相关系数γ≥0.999,检出限为0.0050 mg/kg。6种空白样品中添加双甲脒水平在0.02~1.0 mg/kg时,回收率均值为70.4%~92.9%,相对标准偏差为1.87%~6.55%。该方法简单、快速、准确,且灵敏度好,适用于果蔬中双甲脒及其代谢物残留量的测定。

A determination method for amitraz and metabolite residues in fruits and vegetables was established by using gas chromatography-tandem mass spectrometry through optimizing of the pretreatment process.Amitraz in the samples was hydrolyzed by acid to 2,4-dimethyl aniline in the microwave digestion tank and the hydrolysate was alkalized,extracted with n-hexane,determined by gas chromatography-mass spectrometry and quantified by external standard method.The results showed that the hydrolysates of amitraz at the concentration of 5-2000 ng/mL detected by GC-MS/MS had good linear relation with the mass concentration,with the linear coefficient(γ)≥0.999 and the detection limit 0.0050 mg/kg.The average recovery rates were in the range of 70.4%-92.9%and the relative standard deviations were in the range of1.87%-6.55%when the spiked amitraz concentrations were in the range of 0.02-1.00 mg/kg in 6 blank samples.The proposed method is simple,efficient and accurate with good sensitivity,and could be used for the determination of amitraz and metabolite residues in fruits and vegetables.