APPLICATION OF ION-EXCHANGE-RESIN PHASE SPECTROPHOTOMETRY TO FLOW-INJECTION ANALYSIS SYSTEM .1. DETERMINATION OF TRACE ZINC IN HAIR OF CHILDREN

A novel flow injection analysis system with ion-exchange-resin phase spectrophotometric detection is described in this paper. Zincon was presorbed on the ion-exchange resin. The resin was then added to a flow-through cell. When samples pass through the resin, the zincon presorbed on the resin reacts with zinc(II) to form the zincon-zinc(II) complex, which has an absorption maximum at 620 nm in solution, but at 650 nm in the resin phase. The measurements were made at 650 nm. High sensitivity and precision can be obtained by the proposed method. When 4.0 ml of sample solution was used, the sensitivity obtained was more than 10 times higher than that of the corresponding solution method. The proposed method has been successfully applied to the determination of zinc in the hair of children.