Simultaneous detemination of ferric,ferrous and total iron by extraction differential pulse polarography:application to the speciation of iron in rocks

摘要

The voltammetric characteristics of Fe(III) oxinate at a mercury electrode,in hte presence of 0.2 M tributylammonium perchlorate (tri-BAP) and 0.2M tributylamine (tri-BA) as the supporting electrolyte have been studiedin chloroform.With this supporting electrolyte a two electron quasi-reversible process for the reduction of Fe(III) oxinate was observed.Preceded by a solvent extraction of Fe(III) oxinate in chloroform,differential pulse polarography(DP) was used for the determinatoin of iron.The calibration graph was linear over the concentration range 0.5-50 #mu#M Fe(III) oxinate in chloroform and the detection limit was 1.5 #mu#M.The proposed DP method has been used for the deytermination of the determination of ferric,ferrous and total iron in a mixtute and successfully applied to the speciation of ron in rocks.