Chronopotentiometric stripping analysis of selenium using mercury film electrode

The influence of the most important experimental factors in chronopotentiometric stripping analysis (CSA) of selenium( IV) using mercury film working electrode was examined. Interferences of copper, iron and lead were investigated as well. The possibility of avoiding prolonged deaeration of the solution was examined by applying medium exchange modification of the technique, where the dissolution of the deposit was performed in calcium-chloride solution. Detection limits obtained for the modification of the CSA with prior deaeration and medium exchange modification were 0.4 μg/dmJ and 1.15μg/dmJ, respectively. Accuracy of the defined techniques has been confirmed by analysing reference material (RM 8436) -wheat durum flour. The results obtained by applying both modifications of the technique showed a very good agreement of total selenium content with declareted value