气相色谱-负化学电离质谱法测定食用植物油中5种酰基吡唑类农药残留

建立了气相色谱-负化学电离质谱联用技术测定食用植物油中5种酰基吡唑类农药(呋吡菌胺、吡噻菌胺、氟唑菌苯胺、吡唑特、苄草唑)残留量的检测方法。样品经乙腈冷冻提取,分散固相萃取技术(QuEChERS)净化,采用基质校正曲线外标法定量。在20～1 000μg/L范围内,所有目标物的峰面积与其质量浓度均呈现良好的线性关系,定量限均低于2μg/kg,能满足国内外的限量要求。在0. 01、0. 02、0. 05 mg/kg 3个添加水平下,所有农药的平均回收率均处于82. 7%～112. 4%之间,相对标准偏差≤12. 3%。该法准确度较高,精密度较好,灵敏度高,可用于食用植物油中酰基吡唑类农药残留量的测定。

Determination of five acylpyrazole pesticide residues in edible vegetable oils using gas chromatography-negative chemical ionization-mass spectrometry

A method was established for the determination of five acylpyrazole pesticide residues in edible vegetable oils using gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The pesticides were extracted from a sample with acetonitrile under freezing conditions. A simple cleanup step known as QuEChERS was then conducted. After being identified by GC-NCI-MS, the extracts were quantified using an external standard method that employs a matrix correction standard curve. The linearity of the method was good between 20 and 1000 μg/L, and all limits of quantification were less than 2 μg/kg. Recoveries of all pesticides were in the range of 82.7%-112.4% at the three spiked levels of 0.01, 0.02, and 0.05 mg/kg, and all relative standard deviations were not more than 12.3%. Therefore, this method can be used to determine the residues of acylpyrazole pesticides in edible vegetable oils.