title: Direct zinc determination in commercial sulphuric acid by dpasv. Comparison of rotating disc and stationary graphite electrodes.
abstract: A striking gas technique employed made a direct Zn determination possible at extremely low pH in commercial acid solutions when a stationary impregnated graphite-based mercury film electrode was used. The original Zn(II) concentrations were determined quantitatively by differential pulse anodic stripping voltammetry on 0.5M and 1M sulphuric acid solutions by standard addition and were found to be 2 x 10(-8)M and 4.1 x 10(-8)M, respectively. The influence of mercury ion concentration, pulse amplitude, potential step and pulse repetition time on analytical data was studied and optimized. A rotating disc graphite electrode was also used as a working electrode and was found unreliable for this purpose as hydrogen bubbles were not removed effectively and blocked the working electrode surface.
authors.affiliation: University of Transkei, Department of Chemistry, P/B X1, Umtata, Republic of Transkei, South Africa.
authors.forename: I
authors.initials: I
authors.lastname: Cukrowski
authors.forename: E
authors.initials: E
authors.lastname: Cukrowska