Occurrence of caffeine, saccharin, benzoic acid and sorbic acid in soft drinks and nectars in Portugal and subsequent exposure assessment

Abstract

A reliable method for the determination of benzoic and sorbic acids, caffeine and saccharin in soft drink and nectars using high performance liquid chromatography and UV detection was validated. The chromatographic separation was achieved with a C18 column (250 × 4.6 mm) and one buffered mobile phase, KH 2PO 4 0.02 M/ACN (90:10)/phosphoric acid at pH 4.2. The effluent was monitored at 220 nm. Benzoic acid was detected in 19 soft drinks, being 11 traditional soft drinks and 8 based on mineral water, with mean concentrations of 158 and 148 mg/L, respectively. Fifteen samples, 7 traditional and 8 based on mineral water, contained sorbic acid, with mean concentrations of 172 and 188 mg/L, respectively. Saccharin and caffeine were not detected in soft drinks based on mineral waters. In contrast, 6 samples of traditional drinks contained both additives, with mean levels of 75 and 97 mg/L, respectively. The four additives were not detected in nectar samples. According to European Union and Portuguese legislation, the maximum permitted level (MPL) for benzoic acid was exceeded in 10 soft drinks, and the MPL for sorbic acid overlapped in 3 samples of the referred samples. Two samples exceeded the MPL for the sum of both preservatives, and in 1 sample the MPL for saccharin was overlapped. The estimated daily intakes (EDI) of benzoic, sorbic acid, and saccharin for the average consumer were below the acceptable daily intakes (ADIs). For benzoic acid, the EDIs were 0.25 and 0.32 mg/kg b.w./day, representing 4.9%, and 6.4% of the ADI, respectively for traditional soft drinks and soft drinks based on mineral water. A similar situation was observed for sorbic acid. In this way, the EDIs were 0.17 and 0.41 mg/kg b.w./day, representing only 0.68% and 1.6% of the ADI for the same kind of drinks. For saccharin, the EDI represents 1.28% of the ADI. The EDI for caffeine was 0.08 mg/kg b.w./day.