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为解决蔬菜中农药多残留检测存在的基质复杂、干扰大和浓度低等技术困难,本研究建立了一种新的蔬菜中56种农药多残留的液相色谱-串联质谱的分析方法。蔬菜样品经改良QuEChERS方法前处理,即用含1%(V/V)乙酸的乙腈溶液提取,并加入氯化钠和无水乙酸钠盐析,以N-丙基乙二胺净化,直接进样分析。以乙腈和水溶液(含5 m M的乙酸铵和0.1%(V/V)甲酸)为流动相,经C18色谱柱(4.6×100 mm、2.6μm)分离,电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测。结果表明,56种农药在2μg/L~100μg/L有良好线性,其相关系数大于0.99,检出限均低于0.01 mg/kg,在3个添加水平下的回收率为65.8%~114.0%,相对标准偏差为0.1%~14.5%。该方法简单、快速、可靠,可用于蔬菜质量安全风险评估中多种类农药残留的快速筛查分析。
In order to solve the technical difficulties of complex pesticide residue detection, high interference and low concentration in the detection of pesticide residues in vegetables, a new LC-MS / MS method was developed for the determination of 56 pesticides residues in vegetables. The vegetable samples were pre-treated with a modified QuEChERS method, which was extracted with acetonitrile containing 1% (v / v) acetic acid and salted with sodium chloride and anhydrous sodium acetate, purified with N-propyl ethylenediamine and directly Sample analysis Electrospray positive ion (ESI +) mode ionization was performed on a C18 column (4.6 × 100 mm, 2.6 μm) using acetonitrile and water (containing 5 mM ammonium acetate and 0.1% (v / v) formic acid) , Multiple reaction monitoring (MRM) mode detection. The results showed that 56 kinds of pesticides showed a good linearity in the range of 2μg / L ~ 100μg / L with a correlation coefficient greater than 0.99, and the detection limits were all lower than 0.01 mg / kg. The recoveries were 65.8% ~ 114.0% , Relative standard deviation of 0.1% to 14.5%. The method is simple, rapid and reliable and can be used for the rapid screening analysis of various pesticide residues in vegetable quality safety risk assessment.