固相萃取气相色谱-质谱法测定蔬菜中含氮杂环农药残留

Determination of Nitrogen-containing Heterocyclic Pesticide Residues in Vegetables by Solid-phase Extraction Coupling of Gas Chromatography-Mass Spectrometry

建立了固相萃取（SPE）气相色谱-质谱（GC-MS）同时测定蔬菜中敌菌灵、噻菌灵、氟虫腈和噻嗪酮4种含氮杂环农药残留量的分析方法.蔬菜样品用乙腈匀浆提取后经弗罗里硅（Florisil）固相萃取柱净化.采用GC-MS检测,在选择离子检测（SIM）模式下以特征离子定量,用全扫描（SCAN）方法确证.方法具有良好的线性关系（R≥0.9953）和重现性（峰面积RSD≤9.1%）,最低检出限（S/N=3）在3.6~1.8×10-4μg/mL之间,4种农药添加回收率在76.1%~116.4%之间,RSD≤9.8%,用于实际样品菜心的检测,结果满意.方法操作简单,灵敏度高,可作为测定各种蔬菜基质中含氮杂环农药残留量的确证方法.

A solid-phase extraction（SPE） combined with gas chromatography-mass spectrometry（GC-MS） for the determination of four nitrogen-containing heterocyclic pesticides（anilazine,fipronil,buprofezin,thiabendazole） in vegetables has been developed.The sample was extracted with acetonitrile,purified on a homemade Florisil-SPE column and determined with GC-MS.The analytes were quantitated by monitoring ions and confirmed with the SCAN mode.The method showed good linearity（R≥ 0.9953） and repeatability（RSD ≤ 9.1% for the peak area）.The limits of detection for the four pesticides were between 3.6~1.8×10-4μg/mL（S/N=3）.Recoveries of the four pesticides ranged from 76.1% to 116.4% with RSDs ≤ 9.8%.The method was applied to the determination of trace pesticide residues in flowering Chinese cabbage samples from the local market with satisfactory results.The method is simple,accurate and suitable to the analysis of nitrogen-containing heterocyclic pesticides in vegetables.