Strategy for copper speciation in white wine by differential pulse anodic stripping voltammetry, potentiometry with an ion-selective electrode and kinetic photometric determination

Differential pulse anodic stripping voltammetry (DPASV), potentiometry with a copper ion-selective electrode and a kinetic photometric method were used to determine copper species in white wines. The kinetic method is based on the catalytic effect of labile copper(II) species on the oxidation of 3-hydroxybenzaldehyde azine by potassium peroxidisulfate in an ammonical medium at room temperature. The total copper concentrations were determined by flame atomic absorption spectrometry. Free copper(II) ions, labile and tightly bound copper species could be quantified in 16 non pre-treated wine samples. Received: 13 August 1996 / Revised: 28 October 1996 / Accepted: 29 November 1996