Determination of Iron, Cobalt and Nickel by Reverse Phase High Performance Liquid Chromatography Following Ion Pair Extraction of Metal— 4- (2-Pyridylazo)Resorcinol Complexes

Abstract

Iron, cobalt and nickel-4-(2-pyridylazo) resorcinol complexes are extracted into chloroform with counter-cations. The complexes are separated on a column of Waters µ-BONDAPAK™C₁₈ with the eluent of methanol-chloroform-water containing phosphate buffer (pH 5.0) (53:2:45, v/v) and are detected at 510 nm. The determination limit is 0.50 ppb of cobalt, and 1.50 ppb of iron and nickel when the ion-pair extraction is applied.