AUTOMATIC ADSORPTIVE STRIPPING VOLTAMMETRY AT THIN-MERCURY FILM ELECTRODES (TMFE) - THE HIGHLY-REPRODUCIBLE PLATING AND RENEWING OF THIN MERCURY FILMS ON GLASSY-CARBON FOR THE DETERMINATION OF NICKEL

A procedure for the automated on-line determination of nickel in aquat ic samples was developed. It is based upon adsorptive stripping voltam metry of the dimethylglyoxime complex at a thin-mercury film electrode (TMFE) on glassy carbon substrate. The severe problem of reproducibly renewing the TMFE was solved by the choice of an appropriate electrol yte and a special potential program. With the developed procedure auto matic on-line nickel determinations are possible over extended periods of time with standard deviations not higher than 5% and down to 1.3 p pb nickel.