Solid-phase extraction and high-performance liquid chromatographic separation of pigments of red wines

The adsorption and desorption capacities of 11 different solid-phase extraction sorbents were tested for the preconcentration of pigments of various Hungarian red wines. The concentrates were evaluated by multiwavelengh spectrophotometry combined with a spectral mapping technique (SPM) and by reversed-phase high-performance liquid chromatography. The highest (10-fold) concentration of pigments was achieved on octadecylsilica sorbent. It can be used five times without losing adsorption and desorption characteristics. SPM indicated that multiwavelength spectrophotometry can be employed for the differentiation of red wines. Comparison of the chromatograms of pigments with and without preconcentration showed that preconcentration makes possible the separation and detection of pigments present in low concentration in red wines. (C) 2000 Elsevier Science B.V. All rights reserved.