Simple and environmental friendly procedure for the gas chromatographic–mass spectrometric determination of caffeine in beverages

A simple, quick and organic solvent saving procedure has been developed for the GC/MS determination of caffeine in beverages. The procedure involves the mixing of 25 μL sample with 1 mL ethyl acetate, and a following simple desiccation procedure in a 1.5 mL autosampler vial. A linear calibration curve was generated with caffeine concentration ranging from 0.005 mg/L to 30.0 mg/L. The procedure developed provides a 0.001 mg/L detection limit of caffeine in the final solution by injection of 1 μL solution and the relative standard deviation (RSD) was less than 2% for independent measurement. The total amount of organic solvent used for individual detection is 1 mL of nontoxic ethyl acetate. The developed method was repeatable and could be applied to determine trace amounts of caffeine in popular commercial beverages.