Screen-Printed Carbon Electrode Modified with Poly-L-Histidine Applied to Voltammetric Determination of Chromium (VI)

Abstract

The present work reports the use of a Screen printed carbon electrode (SPCE) modified by poly-L-histidine film to determine Chromium (VI). Stable films can be formed by direct addition of PH solution 1% (w/v) on the electrode surface, followed by heating at 800C during 5 min. Calibration curves can be constructed for Cr(VI) from 1.0 x 10-5 mol L-1 to 7.0 x 10-5 mol L-1 Cr (VI) in acetate buffer pH 4 using a pre-concentration step of 60s at open circuit potential. A relative standard deviation of 3.2% was for five determination of 4.0 x 10-5 mol L-1 Cr (VI). The method was successful applied to determination of Cr(VI) in wastewater samples from a leather dyeing industry.