全自动固相萃取-气相色谱-质谱法测定水中6种苯氧羧酸类除草剂

目的 建立全自动固相萃取-气相色谱-质谱法检测水中6种苯氧羧酸类除草剂的方法.方法 取水样1L,加抗坏血酸除余氯,经浓盐酸调节pH＜1.0,加D3-2,4 二氯苯氧乙酸(D3-2,4-D)内标后混匀,经全自动固相萃取仪上HLB 固相萃取柱萃取,用二氯甲烷洗脱固相萃取柱上吸附的待测物,洗脱液氮吹至1 ml,用三甲基氢氧化...

Determination of 6 phenoxycarboxylic acid herbicides in drinking water by automatic solid phase extraction combined with fully automatic solid phase extraction-gas chromatography-mass spectrometry

Objective To establish a method for the determination of six phenoxycarboxylic acid herbicides by automatic solid phase extraction-gas chromatography mass spectrometry( SPE-GC-MS) in drinking water. Methods After the removal of residual chlorine in the samples with ascorbic acid,the p H of the water samples( 1 L) were adjusted to less than 1. 0 with hydrochloric acid,then the analytes were extracted by HLB SPE cartridges,eluted with dichloromethane and concentrated to1. 0 ml under nitrogen flow. The analytes were derivatized with trimethyl sulfur hydroxide solution and finally detected by gas chromatography-mass spectrometry. Results Good linearity was obtained when the concentration of phenoxy carboxylic acid herbicides in water samples ranged from 10 μg/L to 100 μg/L,the detection limit was 0. 003 g/L,the average standard recovery was within 90. 0%-103. 1%,and the relative standard deviation( RSD) was within 3. 15%-5. 82%. Conclusion The method is quick and accurate and can be applied for the determination of six phenoxycarboxylic acid herbicides in drinking water.