echojwlu
第2楼2006/08/24
在网上搜了一下,有使用ICP-MS测试的,具体应该是先使用层离法把Cr3+分离出来,再对剩余样品进行Cr测试得到结果。以下是英文原文,请大家斧正。
如果都是这样测试的话,我用ICP-AES/ICP-OES也可以得到结果吧?
Separating and detecting Cr is challenging because the common forms of Cr in natural samples such as water are chromate (CrO4 2-) for Cr(VI) and chromic ion (Cr3+) for
Cr(III). Chromate is an anion and the chromic ion is cationic, so a single ion exchange method will not work for both forms under the same conditions. A further problem
is that Cr(III) is the most stable oxidation state in samples such as water, whereas Cr(VI) ions are strong oxidizing agents and are readily reduced to Cr(III) in the presence of acid or organic matter. Consequently great care must be taken during sample collection, storage and preparation, to ensure that the Cr species distribution
present in the original sample is maintained up to the point of analysis. Agilent's newly developed method used an optimized sample stabilization method, in which the samples were incubated at 40°C with EDTA, which forms an anionic complex with the Cr(III), allowing a single chromatographic method to be used to separate the Cr(III)EDTA complex and the Cr(VI).