EXPERT-SYSTEM FOR THE VOLTAMMETRIC DETERMINATION OF TRACE-METALS .3. METHODS FOR DETERMINING MERCURY, SELENIUM AND VANADIUM

A previously described expert system for the voltammetric determinatio n of Cu, Zn, Cd, Pb, In, Ni, Co and Tl is enhanced and improved by mea ns of the addition of methods for Hg, V and Se (optionally also Te). S pecial attention is paid to the determination of V, inside a wide conc entration range, in different types of samples. The system guides the user in the choice of sample treatment and the most appropriate voltam metric procedure for the identification and the quantification of the trace metals. The techniques implemented are differential pulse polaro graphy, anodic stripping voltammetry, cathodic stripping voltammetry a nd adsorptive stripping voltammetry, using mercury drop electrodes and a gold electrode (for the determination of Hg). For the identificatio n and resolution of overlapping peaks (Cd and In), the system may call two external programs, written in turboBasic. Quantification is carri ed out by means of the multiple standard addition method, and the qual ity of the calibration plot is tested by several statistical validatio n tests. The expert system is developed using KES (knowledge engineeri ng system).