Suitability of cyclic voltammetry for the measurement of sodium borohydride (NaBH4) in a solution of Cr(VI)/organic compounds/NaBH4

Cr(VI) reduction by NaBH4 enhanced by organic compounds has been proven to be an effective method. The effort for optimized and efficient application of the method was the reason for the determination of residual NaBH4 in the Cr(VI)/organic compounds/NaBH4 reduction system for reducing agent dosage efficiency. This work showed a suitable detection of NaBH4 standard samples using Pt and Au as working electrode, respectively, and graphite rod as an auxiliary electrode and Ag/AgCl as a reference electrode. In the presence of organic compounds (acetate, citrate, and EDTA), interference was observed in the NaBH4 measurement on Pt electrode making it an unsuitable method for NaBH4 measurement in the presence of organic compounds. As the Au plate electrode was used as a working electrode, NaBH4 solutions measurement in the presence of organic compounds (acetate, citrate and EDTA) by peaks at −0.55 V was found to be affected by the coexisting organic compounds. However, no significant interference of the aforementioned organic compounds was observed at the −0.27 V peak values. The presence of Cr(VI) coexisting with NaBH4 was found to interfere with the NaBH4 measurement using both working electrodes, with a strong correlation between Cr(VI) concentration and the peak values obtained at 0.27 V of Au electrode.