Speciation and determination of Cr(III) and Cr(VI) in water by energy-dispersive PIXE analysis

Recently, water contamination by Cr(VI) has resulted in serious environmental problems. Therefore, many countries are changing the regulation of water quality standard from total chromium to Cr(VI). This study was conducted to develop a sample preparation method for the determination of Cr(III) and Cr(VI) in water by energy-dispersive proton-induced X-ray emission spectrometry. Whatman ion exchange celluloses (P81 and DE81) were used for separation and pre-concentration of Cr(III) and Cr(VI) species by filtration, respectively. The dependences of the limit of detection for both chemical species on the incident proton energy, beam current, and measuring time were examined. The accuracy and precision of the proposed method were determined. The results showed that the proposed method allows the separation and determination of Cr(III) and Cr(VI) with a high accuracy and precision. Copyright (C) 2011 John Wiley & Sons, Ltd.