Ion chromatographic determination of inorganic anions in cola-type beverages

Among foods and beverages with high added phosphate content Cola-type soft drinks are significant contributors to dietary phosphate intake due to the presence of phosphoric acid, used as an acidity regulator. Despite this, current regulations do not mandate manufacturers to disclose the phosphate content of their products. This research aimed to quantify the phosphate content in commercially available cola beverages packaged in aluminium cans. The study employed an ion chromatography system with a suppressed conductivity detector (IC-SCD), utilizing a mixture of aqueous sodium carbonate and sodium bicarbonate as the eluent. This method enabled simultaneous identification and quantification of other inorganic anions such as fluoride, chloride, nitrite, bromide, nitrate, and sulfate. The results showed that three anions (fluoride, bromide, nitrite) were absent in the samples. Chloride concentrations ranged from 4.1 to 81.9 ppm, nitrate from 2.2 to 59.3 ppm, sulfate from 20.5 to 66.8 ppm, and phosphate from 9.2 to 596 ppm. Exploratory data analysis categorized the samples into four groups based on their anion composition. The average phosphate concentration of 455 ppm was below the acceptable daily intake, suggesting that moderate consumption of cola-type beverages does not disproportionately contribute to daily phosphate intake. However, the low pH could potentially damage tooth enamel and cause gastrointestinal problems, while the high sugar content presents an independent health risk, making cola-type beverages unsuitable for a healthy diet.