The Use of Decanol for Improving Chromatographic Stability in Isocratic Non-Aqueous Reversedphase Analysis of Carotenoids by High-Pressure Liquid Chromatography

A non-aqueous isocratic solvent system for reversed-phase analysis of a full range of carotenoids from polar to non-polar is described. The major advance in the method is the use of n-decanol added at 0.1% by volume as modifier to a mobile phase of ethyl acetate-acetonitrile. The presence of the modifier rapidly conditions new columns and avoids problems with trace solvent impurities, both of which would otherwise give unsatisfactory chromatographic behaviour. In the absence of n-decanol, activation of residual silanol groups in the reversed-phase packing can cause a drastic deterioration in column behaviour. The method is rapid, versatile and simple. Information on separation conditions, solvent effects, column conditioning and carotenoid response curves is given.