Determination of methamidophos in water by solid phase extraction-gas chromatography
LIU Na, FENG Guixue, LI Xin, LIU Li, JIA Ruibao
Jinan water and waste water monitoring center, Jinan 250001, China
摘要：建立固相萃取-气相色谱法测定水中甲胺磷的方法。以甲醇为洗脱剂，采用椰壳活性炭固相萃取柱对水样富集，将洗脱液氮吹至近干，然后用乙酸乙酯定容至 1 mL，采用气相色谱火焰热离子检测器（FTD）检测。甲胺磷的质量浓度在 0.1～1.0 mg/L 范围内与色谱峰面积线性关系良好，相关系数为 0.998，甲胺磷的检出限为 0.000 1 mg/L，，定量限为 0.000 4 mg/L。 采用所建方法对实际水样进行测定，地表水和自来水样品加标回收率分别为 83.2%～90.8%、、87.8%～98.8%，测定结果的相对标准偏差分别为 5.5%～8.3%、、7.7%～10%（n=6）。该方法操作简单、有机溶剂用量小，可用于生活饮用水及水源水中甲胺磷的测定。
Abstract：A method for the determination of methamidophos in water by solid phase extraction-gas chromatography was established. Methanol was used as the eluent, and the coconut shell activated carbon solid phase extraction column was used to enrich the water sample. The eluent was dried by nitrogen and diluted to 1 mL with ethyl acetate, and detected by gas chromatography flame thermal ion detector (FTD). The mass concentration of methamidophos had a good linear relationship with the chromatographic peak area in the range of 0.1-1.0 mg/L, and the correlation coefficient was 0.998. The detection limit of methamidophos was 0.000 1 mg/L, and the quantitative limit was 0.000 4 mg/L. The proposed method was applied to the determination of actual water samples. The spiked recoveries of surface water and tap water samples were 83.2%-90.8% and 87.8%-98.8%, respectively,and the relative standard deviations of the determination results were 5.5%-8.3% and 7.7%-10%, respectively (n=6). The method is simple and the amount of organic solvent is small. It can be used for the determination of methamidophos in drinking water and source water.
Keywords：gas chromatography; solid phase extraction; flame thermionic detector; methamidophos
LIU Na，FENG Guixue，LI Xin，et al. Determination of methamidophos in water by solid phase extraction-gas chromatography[J].Chemical Analysis and Meterage，2023，32(10)：7.