Determination of the speciation of chromium with an automated two-column ion-exchange system
Determination of the speciation of chromium with an automated two-column ion-exchange system
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DOI：
10.1016/0003-2670(96)00041-4
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发表时间：
1996-06
影响因子：
6.2
通讯作者：
P. Sule;J. Ingle
中科院分区：
文献类型：
--
作者：
P. Sule;J. Ingle
建立了一种双柱全自动离子交换系统，用于测定水样中铬的形态。该系统基于Chelex-100树脂对阳离子Cr（III）物种的保留和阴离子Cr（VI）物种的阴离子树脂的保留。保留的树脂的铬物种依次洗脱与剥离试剂，并通过在线火焰原子吸收分光光度计检测。阀门和泵的操作、数据采集和数据处理由微型计算机控制。对于Cr（III）和Cr（VI），2 ml样品定量环的检测限为2 ng ml− 1。由Chelex-100保留的Cr（III）的分数随溶液的pH而变化。在腐殖酸的存在下，Cr（III）形成带负电荷的络合物，其中一些被阴离子树脂保留。
An automated two-column ion-exchange system was developed to determine the speciation of chromium in water samples. The system is based on retention of cationic Cr(III) species by Chelex-100 resin and anionic Cr(VI) species by an anion resin. The chromium species retained by the resins are eluted sequentially with stripping reagents and are detected by an on-line flame atomic absorption spectrophotometer. Operation of valves and pumps, data acquisition, and data manipulation are controlled by a microcomputer. The detection limit with a 2 ml sample loop is 2 ng ml−1for Cr(III) and Cr(VI). The fraction of Cr(III) retained by the Chelex-100 varies with the pH of the solution. In the presence of humic acid, Cr(III) forms negatively charged complexes, some of which are retained by the anion resin.