粮谷中抑霉唑残留的气相色谱法测定

Determination of Imazalil Residue in Grain by Gas Chromatography

报道了气相色谱法测定粮谷中抑霉唑残留的方法。选取稻谷、小麦、燕麦和黍（大黄米）4种粮谷产品为研究对象，考察了不同类型检测器、不同提取体系、不同淋洗曲线和不同离心时间的破乳效率对抑霉唑测定的影响。试样以正己烷-乙酸乙酯（体积比1：1）提取，经毛细管气相色谱柱HP-5（30m×0．25mm×0．25μm）分离，μ-ECD检测器测定。方法检出限为0．005mg／kg（S／N=3）。添标水平为0．01、0．05、0．25和0．50mg／kg时平均回收率为82％-111％，相对标准偏差为5．5％-11．5％。线性范围为0.05—1．0mg／L（r^2=0.9994）。该方法快速、灵敏、准确，适合粮谷中抑霉唑残留的测定。

A gas chromatographic method was developed for the determination of imazalil residue in grains including rice, wheat, oat and millet. The effects of different GC detector, extraction reagent, elution system and centrifugal time were investigated. The result indicated that imazalil could be efficiently extracted from grain sample by hexane and ethyl acetate with volume ratio of 1 ： 1, and then analyzed by gas chromatography using HP-5 capillary column （30 m × 0. 25 mm × 0. 25 μm） for separation and micro-electron capture detector（μ-ECD） for detection. The calibration curve showed a good linearity for imazalil concentration in the range of 0. 05 - 1.0 mg/L with a detection limit of 0. 005 mg/kg. Average recoveries of imazalil from grain matrices spiked at four concentration levels of 0.01, 0. 05, 0. 25 and 0.50 mg/kg ranged from 82 % to 111% with relative standard deviations of 5.5% - 11.5% . The proposed method was rapid, sensitive, accurate and low-cost, and was applied in the determination of imazalil in grain sample with satisfactory results.