The proportion of 2-methylbutanol and 3-methylbutanol in some brandies and whiskies as determined by direct gas chromatography

Abstract

Stationary phases suitable for the separation of 2-methylbutanol (“active” pentanol) and 3-methylbutanol (isopentanol) are discussed. The most suitable for the determination of these alcohols in potable spirits by direct injection of samples are diethyl tartrate and polyethylene glycol 200. Polyethylene glycol 200 is preferred because other congeners can be determined at the same time. With n-pentanol as an internal standard, 65 samples of cognac brandies, Scotch and other whiskies have been examined on one or other of these stationary phases. The sum of the two pentanol isomers determined separately agrees well with their determination as a single peak on polyethylene glycol 1500. The ratio of the concentrations of the isomers appears to be characteristic of the type of spirit.