An Investigation on the Extraction and Quantitation of a Hexavalent Chromium in Acrylonitrile Butadiene Styrene Copolymer (ABS) and Printed Circuit Board (PCB) by Ion Chromatography Coupled with Inductively Coupled Plasma Atomic Emission Spectrometry

Abstract

E-mail: shnam@mokpo.ac.krReceived February 17, 2012, Accepted March 19, 2012A hexavalent chromium (Cr (VI)) is one of the hazardous substances regulated by the RoHS. The determinationof Cr (VI) in various polymers and printed circuit board (PCB) has been very important. In this study, the threedifferent analytical methods were investigated for the determination of a hexavalent chromium in AcrylonitrileButadiene Styrene copolymer (ABS) and PCB. The results by three analytical methods were obtained andcompared. An analytical method by UV-Visible spectrometer has been generally used for the determination ofCr (VI) in a sample, but a hexavalent chromium should complex with diphenylcarbazide for the detection inthe method. The complexation did make an adverse effect on the quantitative analysis of Cr (VI) in ABS. Theanalytical method using diphenylcarbazide was also not applicable to printed circuit board (PCB) because PCBcontained lots of irons. The irons interfered with the analysis of hexavalent chromium because those also couldcomplex with diphenylcarbazide. In this study, hexavalent chromiums in PCB have been separated by ionchromatography (IC), then directly and selectively detected by inductively coupled plasma atomic emissionspectrometry (ICP-AES). The quantity of Cr (VI) in PCB was 0.1 mg/kg.Key Words : Acrylonitrile butadiene styrene copolymer (ABS), Printed circuit board (PCB), Ion chromatog-raphy (IC), Inductively coupled plasma atomic emission spectrometry (ICPAES), Hexavalent chromiumIntroductionThe chemical speciation of heavy metals has been verycritical because their bioactivity and toxicity relies on thedifferent chemical forms of heavy metals in a sample.Chromium is one of them because trivalent chromium (Cr(III)) is very essential in nutrition, but hexavalent chromium(Cr VI) is very toxic to human beings.