地下水中铬的分离技术及其应用

Technique for Separation of Chromium Isotope from Groundwater

提出了一种将地下水中的铬与其他基本离子分离的技术,用于固体离子源热电离质谱计(TIMS)测定铬同位素比值。利用铬的氧化态以阴离子形式存在的特点,采用阴离子交换色层分离法将Cr5+与干扰阳离子分离;利用铬的还原态以阳离子形式存在的特点,将Cr3+与硫酸根等干扰阴离子分离。该方法可以成功地应用于地下水中铬同位素信息的测定,在地下水铬污染研究中有着广阔的应用前景。

A method has been developed for separating the Cr dissolved in groundwater from matrix elements and determination of its stable isotope ratios using solid-source thermal-ionization mass spectrometry TIMS. The separation method takes advantage of the existence of the oxidized form of Cr as an oxyanion to separate it from interfering cations using anion-exchange chromatography, and of the reduced form of Cr as a positively charged ion to separate it from interfering anions such as sulfate. Success is made in allowing Cr isotopic signatures to be measured for some groundwater. There is wide application foreground in the research for groundwater contaminated by chromium.