水样中痕量汞的浊点萃取-分光光度法测定

Spectrophotometric Determination of Trace Mercury in Water after Cloud Point Extraction

建立了浊点萃取一分光光度法测定环境水样中痕量汞的方法。在pH=9．0的硼酸钠缓冲溶液中，Hg（11）与双硫腙生成疏水性螯合物。通过40℃水浴加热15min，螯合物被萃取到TritonX114表面活性剂相并与水相分开。将表面活性剂相用乙醇定容至2．0mL，在514nm波长下测定。Hg（1I）在0．1～0．7ug／mI。范围与吸光度有良好的线性关系，检出限（3s／le）为0．0136ug／mL，相对标准偏差为0．80％（n=6）。利用该法富集测定水样中的汞，加标回收率为98．7％～101．7％。

A cloud point extraction process using the nonionic surfactant Triton X-114 for extracting mercury from environmental water by spectrophotometric method was investigated. In Na2 B4 07 buffer solution （pH=9.0）, Hg2＋ reacted with dithizone to form a complex. Using Triton X-114 as the surfactant, the complex was quantitatively extracted into the surfactant-rich phase of small volume. The absorbance was measured at the wavelength of maximum absorbance of the complex, 514 nm, by spectrophotometry. A good linearity was observed for mercury in the range of 0. 1-0. 7 μg/mL with the limit of detection（S/N= 3） of 0. 0136 μg/mL and the relative standard deviation（RSD） of 0.80 （n= 6）. The proposed method was successfully applied to the determination of mercury in environmental water with the recoveries of 98.7 %-101.7 %.