Determination of Zero Retention Times (t₀) by Temperature Dependent Reversed Phase High Perfomance Liquid Chromatography

Abstract

For a given reversed phase HPLC system the zero retention time (t₀) can be determined by measuring brutto retention times at different temperatures. For calculation of t₀ value temperature intervals must be equidistant in 1/T. If at least two compounds are separated on the column having almost the same sorption enthalpies a more simple intersecting point method can be practised. In this case only two temperature points are necessary for graphic evaluation. The presented methods for determination of t₀ values are proved for noradrenaline and adrenaline under selected experimental conditions using aqueous solutions of alkaline perchlorates as mobile phases. Thus t₀ values can be determined with an accuracy and a precision of less than ± 3%.