An on-site colorimetric technique for routine determination of chromium, iron and copper in bath solutions for
Susumu Kawakubo1, Katsuhisa Shimada, Yasutada Suzuki
1Interdisciplinary Graduate School of Medical and Engineering Science, University of Yamanashi, Takeda, Kofu, Japan. akawakubo@yamanashi.ac.jp
Abstract:
An on-site colorimetric technique was developed for the routine determination of chromium, iron and copper in bath solutions for the chromium(III) conversion coating. A portable colorimeter with a red-green-blue light emitting diode was used for the absorbance measurements. Iron and copper were determined as Fe(III)-thiocyanate and Cu(I)-bathocuproindisulfonate, respectively. Chromium(III) was determined simultaneously with iron or copper using green and blue light. A correction method of the matrix effect was proposed and its applicability was demonstrated. Analytical errors were within 500, 5 and 0.3 mg L(-1) for chromium(III), iron and copper, respectively.
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