Chromium speciation by hyphenation of high-performance liquid chromatography to inductively coupled plasma-mass spectrometry -: study of the influence of interfering ions
Chromium speciation by hyphenation of high-performance liquid chromatography to inductively coupled plasma-mass spectrometry -: study of the influence of interfering ions
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DOI：
10.1039/b306249j
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发表时间：
2003-01-01
影响因子：
3.4
通讯作者：
Donard, OFX
中科院分区：
文献类型：
--
作者：
Séby, F;Charles, S;Donard, OFX
本研究建立了一种高效液相色谱-电感耦合等离子体质谱法测定铬的氧化还原形态的方法。使用含有阴离子和阳离子基团的CG 5A-CS 5A柱组（Dionex）进行色谱分离，以分别保留与硝酸洗脱相关的Cr（VI）和Cr（III）。优化后，检测限低于0.5毫克L-1的铬物种。该方法不受氯化物和有机或无机碳对两种最丰富的铬同位素（Cr-52（+）和Cr-53（+））的干扰。然而，在碳酸氢根离子的存在下观察到Cr（III）的化学性质的改变。在该介质中，对于三价铬，色谱图上存在三个峰而不是一个峰。这种修改是由于在这些pH值发生的Cr（III）的水解。通过分析经认证的参比物质（BCR-CRM 544）和加标天然沃茨，验证了分析方法的准确度。发现的Cr（VI）浓度与认证值和加标值非常一致。由于Cr（III）在碱性介质中的高反应性，回收率不完全定量。
This study presents the development of a speciation method for chromium redox species by HPLC-ICPMS. Chromatographic separation is performed with CG5A-CS5A columns set (Dionex) containing both anionic and cationic groups to retain Cr(VI) and Cr(III), respectively, associated with a nitric acid elution. After optimisation, detection limits lower than 0.5 mg L-1 were obtained for both Cr species. This method is free from interferences possibly linked to chloride and organic or inorganic carbon on the two most abundant chromium isotopes (Cr-52(+) and Cr-53(+)). A modification of the chemistry of Cr(III) was, however, observed in the presence of hydrogencarbonate ions. In this medium, for trivalent chromium, three peaks instead of one are present on the chromatograms. This modification was attributed to the hydrolysis of Cr(III) that occurs at these pH values. The accuracy of the analytical procedure was verified by analysing a certified reference material (BCR-CRM 544) and spiked natural waters. The concentrations found for Cr(VI) were in good agreement with the certified and spiked values. Because of the high reactivity of Cr(III) in alkaline medium, recoveries were not completely quantitative.