菌类食品中多种有机磷农药的气相色谱-离子阱二级质谱联用法测定

Determination of Residual Organic Phosphorus Pesticides in Fungi Food by Hyphenation of Gas Chromatography and Tandem Secondary Mass Spectrometry

研究了气相色谱-二级质谱联用技术测定菌类食品中甲胺磷、速灭磷等44种有机磷农药残留的方法,依据待测物化学性质,对预处理方法和质谱分析条件进行了优化。样品加入水浸泡,氯化钠盐析,采用乙酸乙酯-环己烷（1∶1,体积比）匀浆提取2次,合并上层有机相,用无水硫酸钠柱脱水,40℃水浴旋转蒸发至近干,以乙酸乙酯-环己烷（1∶1）定容,凝胶渗透色谱和固相萃取方法（石墨化炭黑小柱）两步净化,氮气吹干后,乙酸乙酯定容至0.25 mL,采用HP-5MS柱,无分流进样,气相色谱-离子阱二级质谱方法进行定性和定量分析,外标法定量。44种农药在0.05-10.00 mg/L范围内呈线性关系,在0.05-0.5 mg/kg加标范围内的回收率为68%-116%,相对标准偏差为5.4%-13.4%,44种有机磷农药的检出限为0.01-0.1mg/kg,满足菌类食品中有机磷农药残留限量的检测。

A method was developed for the determination of 44 organic phosphorus pesticides in fungi food by hyphenation of gas chromatography and tandem secondary mass spectrometry（ GC -MS/MS）. The sample was soaked with water, salted out with NaC1, and extracted twice under ethyl acetate - cyclohexane（ 1 ： 1 ）using homogenate extraction technology. The supernatant was removed water by through a column containing with anhydrous sodium sulfate, and condensed to nearly dry by a rotary evaporator with a 40 ℃ water bath, then redissolve with 10 mL of ethyl acetate - cyclohexane （1 ： 1 ）. The extract was cleaned up by gel permeation chromatography （GPC） and solid-phase extraction（carbon column）, sequencely. The analytes were separated on a HP-SMS chromatographic column with splitless injection mode, and determined by MS/MS using external standard method. A good linearity between the peak area and concentration of acrylamide was obtained in the range of 0. 05 - 10.00 mg/L for all analytes. The recoveries at spiked concentration of 0.05 - 0. 5 mg/kg ranged from 68% to 116% with RSDs of 5.4% -13.4%. The determination limits of 44 organic phosphorus pesticides were in the range of 0.01 - 0. 1 mg/kg. The method could meet the requirement of pesticide residue analysis.