Recoveries were determined by spiking a soft drink known to be free of all additive, in triplicate, with known amounts of saccharin, caffeine, benzoic ans sorbic acid at final concentrations between 40 and 100 mg/L for saccharin, 60 and 250 mg/L for caffeine, 25 and 150 mg/L for benzoic acid, and 50 and 300 mg/L for sorbic acid.