Separation and determination of four artificial sweeteners and citric acid by high-performance anion-exchange chromatography

A high-performance anion-exchange chromatographic method for the simultaneous separation and determination of four artificial sweeteners (sodium saccharin, aspartame, sodium cyclamate and acesulfame-K) and citric acid in a single injection is proposed. The separation was performed by an anion-exchange gradient program and determination by ultraviolet absorbance detection for sodium saccharin, aspartame, acesulfame-K in combination with conductivity detection for sodium saccharin, sodium cyclamate, acesulfame-K as well as citric acid in series. Good linearities between the concentrations of all analytes and relevant peak area responses were achieved over the range 2-100 mu g/ml. The detection limits (signal-to-noise ratio 3:1) were 0.019 mu g/ml for sodium saccharin, 0.035 mu g/ml for aspartame, 0.044 mu g/ml for acesulfame-K by ultraviolet absorbance detection and 0.26 mu g/ml for sodium saccharin, 0.16 mu g/ml for sodium cyclamate, 0.23 mu g/ml for acesulfame-K and 0.22 mu g/ml for citric acid by conductivity detection. The method has been successfully applied to the determination of the four sweeteners and citric acid in drinks and powdered tabletop sweeteners, and the average recoveries for various samples ranged from 93 to 107%.