摘要
利用薄膜扩散技术(DGT)原位富集天然水体中的甲基汞,溶剂洗脱后进入水相进行乙基化反应,与气相色谱(GC)联用,冷原子荧光光谱法(CVAFS)测定。实验结果显示,26℃条件下在超纯水中放置24h,典型DGT单元的最低检出限为0.014ng/L;延长放置时间或者减少扩散层厚度,可以得到更低的检测限。相对标准偏差<10%。该方法具有原位测定、便捷、检测限低、精确度高等优点,是水体中痕量、超痕量甲基汞分析的新方法。
The diffusive gradient in thin films technique (DGT) was developed for measuring methylmercury in nature water by aqueous-phase ethylation reaction with sodium tetraethylborate, gas chromatographic separation, and cold vapor atomic fluores- cence spectrometric detection. This technique is extremely sensitive and relatively efficient because of its in situ pre-concentra- tion. The detection limit of the overall method is 0. 014 ng/L, when deploying a typical DGT device in ultra-pure water for 24 hours, at 26 ~C. Even Iow methylmercury concentrations could be determined using longer deployment times or thinner diffusive gel layer. The relative standard deviation is lower than 10%. This method is an effective in-situ method for trace/ultra trace methylmereury. And it is simple, low detection limited and accuracy.
出处
《地球与环境》
CAS
CSCD
北大核心
2011年第1期130-135,共6页
Earth and Environment
基金
国家自然科学基金资助项目(40721002
20828008)