An assessment of the applicability of the use of a plasticised PVC membrane containing pyrochatecol violet complexing reagent for the determination of Cu2+ ions in aqueous solutions by LIBS

A plasticised PVC membrane containing pyrochatecol violet as complexing reagent has been used to extract and pre-concentrate Cu2+ ions from aqueous solution, aiming at their determination by Laser Induced Breakdown Spectroscopy. The membrane was prepared from a THF cocktail solution on a cellulose acetate support by the dip-coating technique, providing a homogeneous distribution of the complexing reagent and a thickness of 3 mu m. The extraction was straightforwardly performed by immersing the membrane in the Cu2+ sample solution buffered at pH 6.0 with sodium acetate. The extraction time defined the working analytical range (from mu g L-1 to mg L-1) and a 50-mM extraction provided a detection limit of 15 mu g L-1 for Cu2+ ions. The membrane is stable for at least 2 months when stored in a desiccator, allowing in-field extractions, that avoid sampling, storage and transport of the aqueous sample to the laboratory. (C) 2013 Elsevier B.V. All rights reserved.