Abstract
To meet the need for a new and validated analytical method for simultaneous determination of inorganic and organic acid anions in beverage drinks, a capillary zone electrophoresis (CZE) procedure had been developed based on a new background electrolyte (BGE) system containing 3ย mmol/L 1,3,5โbenzenetricarboxylic acid (BTA), 15ย mmol/L tris(hydroxymethyl)aminomethane and 1.5ย mmol/L tetraethylenepentamine (TEPA) at pHย 8.4. Baseline separation of anions commonly found in beverage drinks could be achieved in less than 14ย min with indirect UV detection at 240ย nm. Comigration problems for hydroxycarboxylic acids could be solved using TEPA as BGE additive. The results indicate excellent repeatability for migration time (RSD, 0.27โ0.67%, nย =ย 5) and good precision for both peak height (RSD, 3.2โ4.2%, n = 5) and peak area (RSD, 3.1โ4.5%, n = 5). Under the optimized conditions and using corrected peak area for quantitation, an excellent linear dynamic range (with correlation coefficient > 0.997 in a concentration range from 0.005 to 2.0ย mmol/L) and low detection limit (1โ4ย ฮผmol/L) were obtained for all the anions investigated. The applicability and reliability of the CE procedure developed were established by parallel method determination using established ion chromatography procedure for the analysis of inorganic and organic acid anions in orange juice and wine samples. Our CZE procedure provided a sensitive and economic technique for simultaneous determination of inorganic and organic acid anions in orange juice, red and white wine samples.