Simultaneous Extraction of Cr(III) and Cr(VI) with a Dithiocarbamate Reagent Followed by HPLC Separation for Chromium Speciation
Simultaneous Extraction of Cr(III) and Cr(VI) with a Dithiocarbamate Reagent Followed by HPLC Separation for Chromium Speciation
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使用二硫代氨基甲酸盐试剂同时萃取 Cr(III) 和 Cr(VI)，然后通过 HPLC 分离铬形态
DOI：
10.2116/analsci.20.841
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发表时间：
2004
影响因子：
1.6
通讯作者：
K. Chiu
中科院分区：
文献类型：
--
作者：
Joanna Wang;K. Chiu
研究了一种同时萃取水溶液中Cr^3+和Cr^6+的方法。研究了吡咯烷二硫代氨基甲酸铵（APDC）对Cr^6+和Cr^3+的萃取行为。X射线衍射和光谱研究表明，Cr^6+与吡咯烷二硫代氨基甲酸铵配体反应生成两种产物Cr（PDC）_2（OPDC）和Cr（PDC）_3，其中OPDC代表Cr和S原子之间的氧插入。在邻苯二甲酸盐缓冲液中加入高浓度的APDC，在50°C的温度下进行溶剂萃取，提高了萃取效率，使APDC可以同时萃取Cr^3+和Cr^6+。含氧插入键Cr-O-S的络合物可与正常的Cr（PDC）_3络合物色谱分离，从而允许Cr^6+的定量。Cr^6+的主要产物为Cr（PDC）_2（OPDC），次要产物为Cr（PDC）_3，Cr（PDC）_2（OPDC）/Cr（PDC）_3的比值为8.5。本文报道了Cr^6+和Cr^3+的萃取条件以及用高效液相色谱（HPLC）分离络合物的方法。本文还讨论了SE/HPLC法在环境水溶液中铬化学形态分析中的应用前景。
A simultaneous extraction of Cr^3+ and Cr^6+ species in aqueous solution was developed. The extraction behaviors of ammonium pyrrolidinedithiocarbamate (APDC) for both Cr^6+ and Cr^3+ are carefully discussed in this report. X-ray diffraction and spectroscopic studies indicate that Cr^6+ reacts with the ammonium pyrrolidinedithiocarbamate ligand to form two products, Cr(PDC)_2(OPDC) and Cr(PDC)_3, where OPDC represents an oxygen insertion between Cr and S atoms. A high concentration of APDC in the phthalate buffer under an elevated temperature (50°C) was applied in solvent extraction (SE) to increase the extraction efficiency of Cr^3+, so that both Cr^3+ and Cr^6+ could be extracted by APDC simultaneously. The complex involving the oxygen insertion bonding Cr-O-S is separable from the normal Cr(PDC)_3 complex chromatographically, thus allowing the quantification of Cr^6+. The major product of Cr^6+ has a structure of Cr(PDC)_2(OPDC) and the minor product is Cr(PDC)_3 with a ratio of Cr(PDC)_2(OPDC)/Cr(PDC)_3 being 8.5. The extraction conditions for Cr^6+ and Cr^3+ as well as the chromatographic separation of the complexes using high-performance liquid chromatography (HPLC) are reported. Potential applications for the chemical speciation of chromium by SE/HPLC in environmental aqueous solutions are also discussed.