Rapid Determination of Ortho- and Polyphosphates in Soft Drinks.

Ortho-, poly (pyro- and higher)- and meta-phosphates can be separated from each other with two dimensional thin layer chromatography, the detection level being 1 μg as PO. For determination of ortho- and poly (including polymeta-)-phosphates, an ion-exchange column chromatography was used. A single concentration elution with 0.2 M potassium chloride was effective for separating of orthophosphates from polyphosphates, and the residual polyphosphates could be recovered with 6 N hydrochloric acid. This system was used for a survey of polyphosphates in 61 samples of soft drinks sold in Osaka. Results showed that the total phosphate contents within the range of 0 - 0.420 g of PO/kg. Only three samples contained polyphosphates. The highest being 0.261 g of polyphosphate/kg in a soft drink containing 20% mango juice.