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目的建立全自动固相萃取-气相色谱法检测水中2,4-滴的方法。方法取1 L水样,加浓硫酸使水样p H<1,通过全自动固相萃取仪以15 ml/min将水样过HLB固相萃取柱(Waters,500 mg,Oasis)萃取,用0.1 mol/L Na OH甲醇溶液洗脱HLB固相萃取柱上吸附的待测物,氮气吹干,用三氟化硼甲醇溶液衍生后,加纯水用正己烷提取,经气相色谱仪进行检测。结果水样中2,4-滴的浓度为0μg/ml~1.0μg/ml时,与峰面积呈良好的线性关系,相关系数(r)均>0.999,最低检出浓度为0.01μg/L(1 L水样)。0.1μg/L加标水样组2,4-滴的回收率为110.0%,相对标准偏差(RSD)为6.9%;1.0μg/L加标水样组2,4-滴的回收率为106.0%,RSD为2.3%。结论该方法简便、准确,适用于水中2,4-滴的检测。
Objective To establish a method for the automatic determination of 2,4-D in water by gas chromatography. Methods 1 L water samples were collected, concentrated sulfuric acid was added to make water sample p H <1, and then the water sample was extracted by HLB SPE (15 mg / min, 150 mg, Oasis) using an automatic solid-phase extraction 0.1 mol / L NaOH methanol solution was used to elute the analyte adsorbed on the HLB SPE column, and the mixture was purged with nitrogen and derivatized with boron trifluoride methanol solution. The pure water was extracted with n-hexane and detected by gas chromatography . Results When the concentration of 2,4-D in water was 0μg / ml ~ 1.0μg / ml, the correlation coefficient (r) was> 0.999 and the minimum detectable concentration was 0.01μg / L 1 L water sample). The recovery of 2,4-D in the 0.1μg / L spiked water sample was 110.0%, and the relative standard deviation (RSD) was 6.9%. The recovery of 2,4-D in 1.0μg / L spiked water sample was 106.0 %, RSD was 2.3%. Conclusion The method is simple and accurate and is suitable for the detection of 2,4-D in water.