On-site mine water analysis: application note for the PDV6000plus

This study presents a matrix-removal system for metals that interfere with the determination of arsenic with a voltammetric instrument capable of on-site use. A three-step sample pre-treatment system was developed to remove Fe, Cu and Zn: filtration, adjustment,of pH (pH 5.5) and column-extraction of interfering metals using chelating resin. This set-up allowed the direct and accurate determination of As in mine waters containing up to 1500 mu g L-1 and 500 mu g L-1 Zn and confirmed interferences at higher concentrations. Column optimisation and method adaptation for rapid on-site use are discussed.