Salting-out extraction technique for pretreatment in the liquid chromatographic determination of copper(II), aluminum(III), iron(III) and manganese(II) in biological samples

A solvent extraction method for the simultaneous determination of Cu, Al, Fe and Mn by reversed phase liquid chromatography is presented. The metal chelates with 5-chloro-8-quinolinol are extracted into an acetonitrile phase with tetrabutylammonium perchlorate and ammonium sulfate as salting-out agents, followed by LC separation and determination using an ODS column. The experimental parameters such as the composition of mobile phase and concentration of the salting-out agent for phase separation have been investigated. The mobile phase is a mixture of 3:1 (v/v) acetonitrile-0.02 mol l(-1) sodium acetate solution containing 5x10(-3) mol l(-1) 5-chloro-8-quinolinol. The proposed method has been applied to the trace analysis of Cu, Al, Fe and Al in bovine liver and citrus leaves.