以正己烷-二氯甲烷(3+2)混合液作提取溶剂,对稻谷样品进行超声提取,所得提取液经硅酸镁载体层析柱净化,选择正己烷-丙酮(9+1)混合液作淋洗液。用气相色谱法测定了稻谷中18种有机氯农药和7种多氯联苯的含量。结果表明:此25种化合物的质量浓度均在5.00~200.0 μg·L-1范围内与其相应的峰面积之间呈线性关系。方法的检出限(3S/N)在0.01~0.20 μg·L-1之间。以空白样品作基体进行加标回收试验,测得回收率在71.8%~102%之间,测定值的相对标准偏差(n=6)在2.2%~11%之间。

Sample of rough rice was extracted ultrasonically with a mixture of n-hexane and dichloromethane (3+2). The extract obtained was purified on a chromatographic column filled with florisil, and eluted by a mixture of n-hexane and acetone (9+1). 18 organochlorine pesticides (OCPs) and 7 polychlorobiphenyls (PCBs) in rough rice sample were determined by GC. Linear relationships between values of peak area and mass concentration of the 25 compounds were found in the same range of 5.00-200.0 μg·L-1, with detection limits (3S/N) ranged from 0.01 to 0.20 μg·L-1. Using a blank sample as the matrix, recovery was tested by standard addition method, giving values of recovery in the range of 71.8%-102%, RSDs (n=6) found were in the range of 2.2%-11%.