Gas-Phase Postderivatization Following Solid-Phase Microextraction for Determining Acidic Herbicides in Water
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- 作者：Maw-Rong Lee ; Ren-Jye Lee ; Yih-Wen Lin ; Ching-Ming Chen ; and Bao-Huey Hwang
- 刊名：Analytical Chemistry
- 出版年：1998
- 出版时间：May 1, 1998
- 年：1998
- 卷：70
- 期：9
- 页码：1963 - 1968
- 全文大小：210K
- 年卷期：v.70,no.9(May 1, 1998)
- ISSN：1520-6882
文摘
This study analyzes acidic herbicides from an aqueoussample by developing a methylated postderivatization onthe fiber following solid-phase microextration (SPME) withdiazomethane gas procedure combined with GC/MS.Analysis results indicate that a silica fiber coatedwithpolyacrylate (PA) yields a higher extraction efficiencythanthat obtained with poly(dimethylsiloxane) (PDMS)usingthe SPME technique. Detection limits are achieved atthelevel of 10-30 ng/L. Linearity is obtained over awiderange, with precision below 12% RSD. In addition,thesignificant reduction in extraction efficiency isattributedto the concentration of humic acids exceeding 5 mg/L.Various degradation compounds of acidic herbicides inbasic solution are also detected, including 2,4-dichlorophenol, 2,4,5-trichlorophenol, 4-chloro-3-methylphenol, pentachlorinated biphenyl, and tetrachlorinated biphenyl. Moreover, the amount of pentachlorinatedbiphenyl and tetrachlorinated biphenyl increases overtime.