Simultaneous determination of trace amounts of copper, nickel and vanadium in sea-water by high-performance liquid chromatography after extraction and back-extraction

Abstract

A method for the simultaneous determination of Cu, Ni and V in sea-water by HPLC is described. The complexes of these metals with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)-phenol (5-Br-PAPS) are extracted with capriquat (trioctylmethylammonium chloride) in xylene and back-extracted into sodium perchlorate solution followed by separation and determination by HPLC with an octadecylsilane column and spectrophotometric detection. The conditions of extraction and back-extraction such as, pH, concentration of 5-Br-PAPS or capriquat and concentration of sodium perchlorate are investigated. Linear calibration curve ranges, limits of detection and interferences owing to other ions in sea-water are presented. Application of this method to the trace analysis of Cu, Ni and V in sea-water is demonstrated.