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

Abstract

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 μm. 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 μg L− 1 to mg L− 1) and a 50-min extraction provided a detection limit of 15 μg 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.