气相色谱法测定鱼塘水中2,4-二氯-6-硝基苯酚和五氯酚含量

GC Determination of 2,4-Dichloro-6-nitrophenol and Pentachlorophenol in Fishpond Water

鱼塘水中残留的2种除草剂(2,4-二氯-6-硝基苯酚和五氯酚)经GDX201固相萃取柱富集后,用二氯甲烷洗脱,洗脱液用N-(叔丁基二甲硅烷基)-N甲基三氟乙酰胺衍生化,所得衍生化产物溶于乙酸乙酯中,用气相色谱法测定,从而获得上述2种除草剂的含量。2,4-二氯-6-硝基苯酚和五氯酚的峰面积与其质量浓度均在10～200μg.L-1内呈线性关系,检出限(3S/N)分别为0.09μg.L-1和0.16μg.L-1。以鱼塘水为基体进行加标回收试验,测得回收率依次为98.3%,98.6%;测定值的相对标准偏差(n=5)分别为3.6%和4.3%。

Two residual herbicides, i. e., 2,4-dichloro-6-nitrophenol and pentachlorophenol, in sample of fishpond water were enriched by SPE on GDXz01 column, and eluted with methylene chloride. The eluate obtained was then derivatized with N-（tert-butyldimethylsilyl）-N-methyl-trifluoroaeetarnide, and the derivatized products in ethyl acetate were determined by CA2, from which contents of the 2 herbicides were obtained. Linear relationships between values of peak area and mass concentration of 2, 4-dichloro-6-nitrophenol and pentachlorophenol were obtained in the same range of 10--200μg.L-1 , with limits of detection （3S/N） of 0. 09μg.L-1 and 0. 16 μg.L-1 respectively. Tests for recovery and precision were made by standard addition method using fishpond water as matrix, giving values of average recovery of 98. 3% for 2, 4-dichloro-6-nitrophenol, and 98. 6% for pentachlorophenol with RSD＇s （n=5） of 3.6% and 4. 3% respectively.