吹扫捕集-GC-MS测定水中痕量氯乙酸的研究

Study on Determination of Trace Chloroacetic Acids in Water Using Purge and Trap-GC-MS

固相萃取-吹扫捕集-气质联用法对一氯乙酸、二氯乙酸、三氯乙酸进行分析,水样体积为200 mL时,此方法检出限分别为:0.004 mg/L、0.0008 mg/L、0.002 mg/L,加标回收率为94%～107%,5次平行测定的相对标准偏差为3.78%～5.96%。取1000 mL广州市自来水测定其中氯乙酸含量的结果是:一氯乙酸5.37μg/L、二氯乙酸10.84μg/L、三氯乙酸8.74μg/L。

The analytical performance of techniques based on the combination of solid phase extraction and purge and trap with gas chromatography-mass spectrometry were studied. It was found that the detection limits for monochloroacetie acid, diehloroaeefic acid and trichloroacetic acid by purge and trap were 0.004 mg/L, 0.0008 mg/L and 0.002 mg/L, respectively. The recovery was in the range of 94 %-107 % with RSD （n-5） of 3.78 %5.96 %. By the proposed method, the contents of monoehloroacetie acid, diehloroaeetic acid and trichloroacetic acid in tap water samples collected from Guangzhou were found to be 5.37 μg/L, 10.84 μg/L and 8.74 μg /L, respectively.