Analysis of German Wines by Gas Chromatography and Atomic Absorption

Abstract

An analytical profile of a total of 49 samples of 1970 and 1971 vintage Rhine and Moselle German white wine is presented. The data include atomic absorption analysis for the elements K, Na, Mg, Ca, Fe, Cu, and Zn; gas-liquid chromatographic analysis for methanol, ethyl acetate, n-propyl alcohol, iso-butyl alcohol, and iso-amyl alcohol; the traditional specific gravity determination for ethanol; and the determinations for total acids, solids, and ash. For each of the parameters determined the range, mean and standard deviation is given. A comparison of the data for the 1970 and 1971 vintage years and the Rhine and Moselle wine regions is included. The conclusion is drawn that the data are insufficient to determine distinguishing and identifying characteristics of either vintage year or wine region.

Bias in Wilks' A in Stepwise Discriminant Analysis

“…They computed range, mean and standard deviation for each variable and from a visual examination concluded that the data showed no apparent separation. Kwan and Kowalski (1978) performed further analysis of the data of Dyer and Ansher (1977). They extended the original 16 variables by including all possible ratios, for a total of 256 variables.…”

“…6. EXAMPLE Dyer and Ansher (1977) collected data on 1970 and 1971 vintage Rhine and Moselle German white wines to determine if vintage year and wine regions could be distinguished by a chemical and spectrographic analysis. They measured concentration levels of 16 major components in wine: atomic absorption analysis for elemental compositions, gas chromatographic analysis for alcohols and determination of total acids, solids and ash.…”

Maceration affects mineral composition and pH of wines

“…Potassium in wines can reach 370-1160 mg/l Eschnauer, 1988;Zee et al 1983;Dyer-Ansher, 1977). In Hungary 550-1800 mg/l (Diófási et al, 1983;Szitha et al, 1985) was measured.…”

“…Excessive use of potassium in plant nutrition can be a reason for its higher level in wine, however this could entail other plant physiological disorders like bunch stem necrosis by defecting K/Mg-ratio. According to Dyer-Ansher (1977) red wines usually contain more potassium.…”

“…Turbidity resulting from this criterion must be taken in count over 80 mg/l calcium content (Madau et al, 1990;Goranov, 1979). Since fining of wines with bentonite can increase its presence (Postel et al, 1987) with about 10-15%, and application of calcium carbonate in deacidification can entail a 50-100% increase (Dyer-Ansher, 1977), calcium level of the must is normally lower than that of the wine. Two other alkali earth metals can be found in wines in a much lower concentration.…”