固相微萃取(SPME)-气质(GC/MS)联用法分析饮用水中痕量碘代三卤甲烷

Analysis of trace I-DBPs in drinking water by SPME-GC/MS

碘代消毒副产物（I-DBPS）是饮用水消毒过程中发现的一类暂未受控的新兴高致毒性消毒副产物。为了便于对饮用水中I-DBPS进行研究,可采用固相微萃取（SPME）-气质（GC/MS）联用技术来检测分析,介绍了固相微萃取的装置、操作及萃取方法,着重论述了其工作条件的选择,得出最佳优化条件：以DVB/CAR/PDMS作为萃取膜,萃取温度为65℃,萃取时间为45min,离子强度用25%（W/V）Na2SO4调节,搅拌速率为250r/min,并且在气相色谱中的解析温度为220℃,解析时间为30s。同时进行重复性和再现性试验对方法的检测限、精确度与准确度进行了评价。结果表明,采用SPME-GC/MS方法,分析物的检测限在10～50ng/L,可以用来检测ng/L级水平的痕量碘代三卤甲烷（I-THMS）,且在分析物标准浓度为0.1μg/L时,重复性试验的相关标准偏差（RSD）在0.4%～1.5%,再现性试验的RSD在4%～12.5%,这表明该方法应用于痕量I-DBPS的分析检测是精确可靠的。

The iodine-disinfection by-products（I-DBPs）are a kind of disinfection by-products which were newly found in the process of drinking water disinfection.In this research,solid-phase micro extraction（SPME）-GC/MS was used to study I-DBPs.Meanwhile,the installation and operation of SPME and the methods for extraction were also introduced in this paper.In addition,this paper also highlighted the choosing of working conditions for extraction and analysis.In the end,this paper proposed the most suitable condition for extraction and analysis as follow：the DVB/CAR/PDMS should be used as extraction disks;the extraction temperature should be 65℃and duration time 45 min,accordingly;the 25%（W/V）Na2SO4should be used to regulate the ionic strength;the mixing rate should be about 250rmp;the temperature of desorption in gas chromatography might be 220℃and the desorption should last for 30 s.In this paper,repeatability and reproducibility experiments were applied to test the detection limits,precision and accuracy of SPME-GC/ME.The results showed that if the detection limit of analysis was 10~50ng/L,the SPME-GC/MS could be adopted to test the trace I-THMs at ng/L level;the standard concentration of analysis was 0.1μg/L;the RSD of repeatability and reproducibility experiments were 0.4%~1.5%and 4%~12.5%,respectively.These data indicated that it would be accurate and reliable to use SPMEGC/MS to detect and analyze I-DBPs.