Trace metal studies of selected white wines: an alternative approach

A number of white wines from vineyards outside the metropolitan region of Melbourne were analyzed for the trace metals copper, iron, potassium, sodium, magnesium and calcium by atomic absorption spectrometry (AAS). The 24 wines analyzed included Chardonnay, Sauvignon Blanc, Riesling Gewurztraminer and Pinot Gris. In addition, preliminary transmission near infrared (NIR) spectrometric analyses for these metals in the above wines indicated, using both multiple linear regression (MLR) and partial least squares (PLS), that promising results may be obtained for some metals. The squared correlation coefficients (R-2) and the ratios of the standard error of cross validation (SECV) and the standard deviation (S.D.) for the calibration models for potassium, sodium, magnesium and calcium were acceptable, however those for iron and copper were not. Although, only a small number of wines were used in this study, the preliminary data indicated that NIR spectrometry may provide a suitable, rapid method for analysis for some metals in white wines, and warrants a further investigation using a larger number of white wines over a wider range of locations. (C) 2002 Elsevier Science B.V. All rights reserved.