ANALYTICAL REVIEW OF VOLTAMMETRIC METHODS FOR THE DETERMINATION OF SELENIUM

The review article discusses the characteristic features of the voltammetric determination of selenium, which is a necessary element in low concentrations for humans, animals, plants, but has a toxic effect at elevated levels, which leads to a chronic disease – selenosis. Of the large variety of analytical methods for determining various forms of selenium, electrochemical methods are currently preferred, due to the simplicity of preparing samples for analysis, the cheapness and availability of the equipment used while maintaining high sensitivity and expressiveness of measurements, sometimes reaching picomolar concentrations when using inversion voltammetry. Various working electrodes based on mercury, carbon, silver, platinum and gold materials were used to analyze selenium in various samples. Only selenium in the oxidation state (+4) is electroactive, so most voltammetric definitions are devoted to it. However, with the modification of electroanalytical approaches, other forms of selenium can be detected. Trends in the development of selenium electroanalytics with the use of modified electrodes, such as electrodes obtained by screen printing (screen printed electrode), and modified with a film of bismuth, gold, silver, nanoparticles of these metals of various shapes and other organic compounds are considered.