Preconcentration and colorimetric determination of Fe (III) by sequential injection analysis

Abstract

A sequential injection analysis (SIA) assembly for the photometric determination of Fe(III) in fresh- and seawater is proposed. Iron is preconcentrated on a microcolumn packed with a chelating resin (Chelex 100) that is inserted in the manifold. The sample is passed through the column, and the iron retained by the resin is subsequently eluted with 2 M HNO3. The Fe-KSCN complex is detected by UV-vis spectrophotometry. The proposed SIA system affords automatic preconcentration, elution, and formation of the iron thiocyanate complex. The detection limit thus achieved is 0.02 mg/L, and the relative standard deviation 3%. © 1996 John Wiley & Sons, Inc.