EN
The aim of this study was to isolate different forms of selenium and determine their mobility in aqueous solution by means of paper electrophoresis. Sodium selenite (Na2SeO3) and sodium selenate (Na2SeO4) were tested. Solution mixtures containing SeO32- and SeO42-- ions were prepared. The main electrolyte in our experiment was 0.1 mol/dm3 solution of NaClO4. 4% 3,3'-diaminobenzidine (DAB) was used as the reagent. 27 x 2 cm strips of Whatman 2 blotting paper were used as the carrier. DESAGA GmbH apparatus was used for electrophoresis. The optimum parameters of the isolation process were selected by trial and error. The following optimum values were chosen: isolation time 3600 s, voltage 1000 V, temperature 5°C, applied solution volume 5 µl. The mobility of the SeO32- and SeO42- ions was calculated from the formula: u = s x 1 / E x Ł, where u = mobility [cm2/Vs], s = distance of migration in the electric field [cm], 1 = distance between electrodes [cm], E = voltage [V], 1 = isolation time [s]. The value of the mobility was relatively low: from 0.12 x 10-4 to 0.36 x 10-4 [cm2/Vs] for SeO32- and from 0.07 x 10-4 to 0.42 x [cm2/Vs] for SeO42- ions. The mobility of the SeO42- ions in the studied solutions was found to be lower. A considerable diversity of selenium forms was detected in the studied solutions.