DETERMINATION OF COPPER, LEAD AND CADMIUM IN WHOLE-BLOOD BY STRIPPINGVOLTAMMETRY WITH THE USE OF GRAPHITE-ELECTRODES

The problem with toxic metal ion determination in blood is the adsorpt ion of organic compounds on the electrode surface and the formation of complexes between metal ions and organic constituents of blood. This is the reason why usually preliminary acid digestion or other sample p retreatment is used. Two kinds of electrodes have been used: ''Ultra-T race Electrode'', made from impregnated graphite (I), and thick film g raphite disposable electrodes (II). The analysis of whole blood with d ifferent sample preparation methods shows, that chemical digestion is not necessary for the analysis. Electrochemical two-stage sample prepa ration provides the possibility for analysing whole blood with the men tioned electrodes. Thick film disposable electrodes are less sensitive to the interference of organic constituents of blood. These electrode s give the possibility to determine total cadmium, lead and copper con centration in whole blood without special sample pretreatment. The app lication of ''Ultra-Trace Electrode'' for blood analysis is possible o nly after preliminary pretreatment of blood by chemical digestion or e lectrochemical sample preparation.