Sun Yali, Sun Min, Zhao Guochun
Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Wushan, guangzhou, China.
Anal Sci. 2006 Apr;22(4):551-5. doi: 10.2116/analsci.22.551.
This study developed a methodology to analyze trace rare earth elements (REEs) in geological materials by capillary electrophoresis (CE). Changed from dilute HNO3 into a water medium by heating, REE ions are detectable at approximately 2 ng mL(-1). In the presence of coexisting elements from geological samples, REE separations were carried out. After sample fusion with Na2O2 and interference separation with ammonium pyrrolidinedithiocarbamate chelate, REE analytes were coprecipitated with Mg(OH)2 at pH 8.5, and then prepared into a water medium for CE determination. Using the standard addition method, this protocol was validated by analyses with better than 5% precision. This method was applied to geological materials; the REE results are in consistence with their certified values. With electrokinetic injection, internal standard (IS) selected among lanthanides is a prerequisite of high-quality REE data. An approach was proposed to derive the IS content for further correcting its contribution from unknown samples.
本研究开发了一种通过毛细管电泳（CE）分析地质材料中痕量稀土元素（REEs）的方法。通过加热将介质从稀硝酸改为水介质后，REE离子在约2 ng mL(-1)时可被检测到。在地质样品中共存元素存在的情况下，进行了REE分离。样品与Na2O2熔融并与吡咯烷二硫代氨基甲酸盐螯合物进行干扰分离后，REE分析物在pH 8.5时与Mg(OH)2共沉淀，然后制备成水介质用于CE测定。采用标准加入法，该方法经分析验证，精密度优于5%。该方法应用于地质材料；REE结果与认证值一致。采用电动进样时，从镧系元素中选择内标（IS）是获得高质量REE数据的前提。提出了一种方法来推导IS含量，以进一步校正其对未知样品的贡献。
