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目的建立气相色谱-串联质谱法快速测定水中5种除草剂。方法水样采集后,采用石油醚分次萃取,合并萃取液旋转蒸发后用丙酮定容,气相色谱-串联质谱直接测定,根据保留时间定性,标准曲线法定量。结果水中5种除草剂在0.02~1.0 mg/L范围内具有良好的线性,相关系数均≥0.999。对于500 ml水样,本方法的检出限分别为甲草胺0.01μg/L、乙草胺0.01μg/L、丁草胺0.02μg/L、莠去津0.01μg/L、扑草净0.01μg/L。5种除草剂测定的日内精密度为1.6%~7.0%,日间精密度为2.7%~6.9%;加标回收率分别为甲草胺81.7%~85.6%,乙草胺87.4%~95.4%,丁草胺87.7%~91.2%,莠去津84.5%~92.3%,扑草净86.2%~92.5%。结论建立了同时快速测定水中五种除草剂的气相色谱-串联质谱法,具有操作简单、快速、选择性好、准确度高等特点,适用于同类别除草剂污染水体的大量样品的快速筛查和测定。
Objective To establish a rapid method for the determination of five herbicides in water by gas chromatography-tandem mass spectrometry. Methods After the water sample was collected, petroleum ether was used for fractional extraction. The combined extracts were subjected to rotary evaporation and then to acetone for volume determination. Gas chromatography-tandem mass spectrometry was used for the direct determination, which was characterized by retention time and standard curve method. Results The results showed that the five herbicides in water had a good linearity in the range of 0.02-1.0 mg / L with correlation coefficients ≥0.999. For the 500 ml water samples, the detection limits of this method were: alachlor 0.01 μg / L, acetochlor 0.01 μg / L, butachlor 0.02 μg / L, atrazine 0.1 μg / L, μg / L. The intra-day precision of the five herbicides was 1.6% -7.0% and the intra-day precision was 2.7% -6.9%. The recoveries of the five herbicides were 81.7% -85.6% for alachlor, 87.4% -95.4% for acetochlor, , Butachlor 87.7% ~ 91.2%, atrazine 84.5% ~ 92.3%, prometryn 86.2% ~ 92.5%. Conclusion Gas chromatography-tandem mass spectrometry (LC-MS / MS) method was established for the rapid determination of five herbicides in water at the same time. The method has the advantages of simple operation, fastness, good selectivity and high accuracy. The method is suitable for the rapid screening of a large number of samples contaminated with water by the same type of herbicide Determination.