Determination of purine alkaloids and trigonelline in instant coffee and other beverages using high performance liquid chromatography

Abstract

Abstract A simple, rapid high performance liquid chromatography method is reported for the simultaneous analysis of trigonelline and caffeine (1,3,7‐trimethylxanthine) in coffee, and theobromine (3,7‐dimethylxanthine) and caffeine in samples of cocoa, drinking chocolate, tea and cola. Chromatography was carried out on Spherisorb‐ODS columns with gradient elution. The eluate was monitored at 272 nm with an ultraviolet spectrophotometer and quantification was achieved with external standards. Results for different brands of instant coffees, one decaffeinated coffee, and for samples of cocoa, drinking chocolate, tea and cola are reported.