Potentiometric and spectrophotometric determination of phosphoric acid in some beverages

Research Article

Pius I. Utange, Raymond A. Wua

Abstract

The Potentiometric and spectrophotometric determination of phosphoric acid content was conducted on three batches of selected beverages: Regular and Light Coke, Regular and Light Pepsi, Smirnoff Ice and 7 Up with 7 Up as control. The phosphoric acid content (mg P/L) in the three batches of these beverages using potentiometric method were: Light Coke - 136.9±5.9, 139.500±0, 139.500±0; Regular Coke - 183.4±3.9, 175.2±0.8, 174.4±2.3; Light Pepsi - 170.5±2.1, 172.8±3.6, 164.6±2.0; Regular Pepsi - 139.8±4.5, 141.6±3.1, 140.0±0.9; Smirnoff Ice - 2244.9±44.7, 2166.9±40.6, 2087.3±28.6. The results of the spectrophotometric method were respectively: Light Coke - 226.7±3.7, 207.2±1.8, 224.6±2.0; Regular Coke - 218.4±2.7, 271.8±3.3, 242.7±1.6; Light Pepsi - 220.4±2.4, 252.9±2.3, 254.9±1.2; Regular Pepsi - 237.3±1.4, 256.2±1.2, 255.6±1.8; Smirnoff Ice – 916.1±25.5, 969.1±10.7, and 923.2±19.7. 7 Up however, did not contain phosphoric acid. Analyses of variance using Student’s t test showed that at 0.05 level, there was no significant statistical difference between the two methods employed as TcalHtab (7.20 > 5.99). The extremely low pH values of the beverages (2.15 – 2.85) may account for the claims of authors of being associated with cariogenicity. The phosphoric acid contents of these beverages (207.241±1.751 – 969.147±10.743 mg.P/L) pose some health concern.

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