提出了气相色谱法测定葵花籽中55种有机磷农药残留量的方法。样品用乙酸乙酯-环己烷(1+1)混合液提取,所得提取液须经凝胶渗透色谱净化除去大分子干扰物质。方法中采用Bio-Beads S-X3凝胶渗透色谱净化柱和乙酸乙酯-环己烷(1+1)混合液作流动相。所得淋出液中的55种有机磷农药再经DB-1701色谱柱(30 m×0.25 mm,0.25 μm)分离后,用火焰光度检测器检测。55种有机磷农药的质量浓度均在一定的范围内与峰面积呈线性关系,方法的检出限(10S/N)在0.002 5~0.05 mg·kg-1之间。在3个浓度水平下对方法的回收率和精密度进行了试验,测得回收率在53.5%~119%之间,测定值的相对标准偏差(n=6)均小于14%。

A method of GC for determination of residual amounts of 55 organophosphorus pesticides in sunflower seeds was proposed. The sample was extracted with a mixture of ethyl acetate and cyclohexane (1+1), and the extracts obtained were purified to remove the macromolecular impurities by gel permeation chromatography (GPC), using Bio-Beads S-X3 GPC column and the same mixture of ethyl acetate and cyclohexane (1+1) as mobile phase. The 55 organophosphorus pesticides in the eluate were separated on DB-1701 (30 m×0.25 mm, 0.25 μm) column and determined by flame photometric detector. Linear relationships between values of peak area and mass concentration of the 55 organophosphorus pesticides were kept in definite ranges, with detection limits (10S/N) in the range of 0.002 5-0.05 mg·kg-1. Recovery and precision of the method were tested at 3 concentration levels, giving results of recovery in the range of 53.5%-119% and RSD′s (n=6) less than 14%.