Department of Environmental Science, Faculty of Science and Technology, Suan Dusit Rajabhat University, 10300, Thailand.
J Hazard Mater. 2010 Aug 15;180(1-3):759-63. doi: 10.1016/j.jhazmat.2010.03.090. Epub 2010 Mar 25.
New measurements using extended X-ray absorption fine structure (EXAFS) and electron paramagnetic resonance (EPR) techniques are consistent with Cr in the Cr(III) oxidation state as the main product from the adsorption of Cr(VI) on coir pith. These confirm the previous X-ray measurements, but differ from the results of previous EPR studies, which indicated that Cr(V) was the main form of Cr. The reason for this discrepancy is the presence of a broad signal from Cr(III) in an unsymmetrical environment that was missed previously; the Cr(V) component is in fact only a minor reaction product. As a result of this problem with spectral acquisition and interpretation, some simple recommendations are presented for conducting EPR investigations on natural systems.
利用扩展 X 射线吸收精细结构（EXAFS）和电子顺磁共振（EPR）技术进行的新测量结果表明，在椰壳纤维上吸附 Cr(VI) 后，主要产物是处于 Cr(III) 氧化态的 Cr。这些结果与之前的 X 射线测量结果一致，但与之前 EPR 研究的结果不同，后者表明 Cr(V) 是 Cr 的主要形态。造成这种差异的原因是之前未被发现的来自处于非对称环境中的 Cr(III)的宽信号；Cr(V) 组分实际上只是一个次要的反应产物。由于在光谱获取和解释方面存在这个问题，因此针对在自然系统中进行 EPR 研究提出了一些简单的建议。
