Wybrane techniki woltamperometrii inwersyjnej i cyklicznej
w analizie substancji leczniczych
Selected techniques of inverse and cyclic voltammetry in the analysis of pharmaceutical substances. The short review of voltammetric analysis of drugs is presented along with some theoretical background. Different techniques of inverse voltammetry are very widely used in pharmaceutical analysis because of low detection levels, accuracy, precision and low cost of instrumentation in comparison to other physicochemical methods of analysis. In trace analysis of drugs the accumulation of the analysed compound must be carried out. If the accumulation is followed by oxidation of the substance under investigation, the method is called anodic stripping analysis (ASV), if by reduction, it is called cathodic stripping analysis (CSV). In inverse voltammery different types of working electrodes can be used, e.g. the hanging mercury electrode, the thin mercury film electrode, the wax-impregnated graphite electrode, carbon paste electrodes and glassy carbon electrodes. Electrodes made of noble metals (gold or platinum) are used less frequently. There is quite a number of voltammetric techniques which differ in the manner that the potential of working electrode is changed during the experiment. In some techniques, a linear potential sweep is applied to the working electrode, in others, a potential step or pulse sequence is used.