Chromium Determination in Osteoblast-Like Cell Culture Medium by Catalytic Cathodic Stripping Voltammetry with a Mercury Microelectrode

Abstract

A catalytic cathodic stripping voltammetric procedure for the determination of total chromium in osteoblast-like cell culture medium using a mercury film microelectrode (MFM) was optimised. The method is based on the pre-concentration of the Cr(III)-diethylenetriaminepentaacetic acid (DTPA) complex by adsorption at the potential of-1.00 V (vs. Ag/AgC1) in the presence of 10 x 10(-3) mol/L DTPA, 0.70 mol/L sodium nitrate, 0.04 mol/L sodium acetate and 1.0 x 10(-3) mol/L potassium permanganate at pH 5.9-6.0. The limit of detection obtained for a 40 s collection time was 2.80 x 10(-10) mol/L of chromium. The results achieved by stripping voltammetry using the MFM were compared to those obtained by atomic absorption spectrometry (AAS) to ensure the reliability of the electrochemical method. This procedure proved to be an alternative to AAS and valuable in biocompatibility studies performed in vitro using osteoblast-like cells.