Classification of multiple defect concentrations in white wine by platinum microelectrode voltammetry

Concentrations of defect pairs added to a white wine were classified by voltammetric measurements on interdigitated platinum microelectrodes using principal component analysis of the current responses. Combinations of 0, 1, 2 and 3 mM concentrations were investigated. The defect pair ascorbic acid/acetaldehyde exhibited little interaction with each other and the pair-wise concentrations were symmetrically positioned in a score plot around a center axis of equimolar concentrations. The ascorbic acid/sulfur dioxide pair exhibited a center axis for the equimolar concentrations shifted toward the 3 mM sulfur dioxide sample. The defect pair having the strongest interaction through complex formation, acetaldehyde/sulfur dioxide, had the equimolar concentrations in score plots located near the white wine control sample.