Chromium speciation using aqueous biphasic systems: Development and mechanistic aspects
Chromium speciation using aqueous biphasic systems: Development and mechanistic aspects
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DOI：
10.1016/j.seppur.2015.12.013
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发表时间：
2016-01
影响因子：
8.6
通讯作者：
P. Patrício;R. D. D. Cunha-R.-D.-D.-Cunha-2092212953;S. Vargas;Y. Coelho;L. D. Silva;M. C. H. D. Silva
中科院分区：
文献类型：
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作者：
P. Patrício;R. D. D. Cunha-R.-D.-D.-Cunha-2092212953;S. Vargas;Y. Coelho;L. D. Silva;M. C. H. D. Silva
铬的两种主要氧化态在其生物学和毒理学性质上存在显著差异，区分它们非常重要。开发高效、快速、简便和廉价的铬形态分析方法是一项分析挑战。研究了在无萃取剂存在下，聚氧化乙烯（PEO 1500）或三嵌段共聚物（L 64）、电解质（Li 2SO 4、Na 2SO 4、MgSO 4、C6 H5 Na 3 O 7或C4 H4 Na 2 O 6）和水组成的水两相体系（ABS）中铬的形态。Cr（III）有利地分配到ABS的富电解质相（ERP），而Cr（VI）在大多数分析的ABS中优先集中在富大分子相（MRP）。荧光光谱数据显示，Cr（III）和Cr（VI）的分离过程是由特定的相互作用之间的环氧乙烷片段的大分子和Cr（VI）的物种，这不会发生的Cr（III）的物种。从ERP到MRP的铬物种的提取百分比（%E）受pH值，连接线长度（TLL），电解质性质和大分子疏水性的影响。对于包含PEO 1500 + Na 2SO 4 + H2O、TLL = 50.89%（m/m）、25 ℃和pH 2.0的ABS，Cr（III）和Cr（VI）的%E值分别为0.0100和99.9%。在该ABS中实现的Cr（III）和Cr（VI）的形态导致1.00 × 108的优异分离因子（SCr（VI），Cr（III））。
The two principal oxidation states of chromium diverge significantly in their biological and toxicological properties, and it is very important to distinguish between them. Develop procedures that are efficient, fast, easier and cheaper for chromium speciation is an analytical challenge. Chromium speciation was investigated using aqueous biphasic systems (ABS) formed by polyethylene oxide (PEO1500) or a triblock copolymer (L64), an electrolyte (Li2SO4, Na2SO4, MgSO4, C6H5Na3O7, or C4H4Na2O6) and water, without the presence of any extractant. Cr(III) was favorably partitioned to the electrolyte-rich phase (ERP) of the ABS, whereas the Cr(VI) was preferentially concentrated in the macromolecule-rich phase (MRP) in most analyzed ABS. The fluorescence spectroscopy data revealed that the Cr(III) and Cr(VI) separation process is governed by specific interactions between the ethylene oxide segments in the macromolecules and the Cr(VI) species, which do not occur for Cr(III) species. The extraction percentage (%E) of chromium species from the ERP to the MRP was affected by pH, tie-line length (TLL), electrolyte nature, and macromolecule hydrophobicity. For the ABS comprising of PEO1500 + Na2SO4+ H2O, TLL = 50.89% (m/m), 25 °C and pH 2.0, the %Evalues for Cr(III) and Cr(VI) were 0.0100 and 99.9%, respectively. The speciation of Cr(III) and Cr(VI) that was achieved in this ABS resulted in an excellent separation factor (SCr(VI),Cr(III)) of 1.00 × 108.