An Ion‐Pair High Performance Liquid Chromatographic Method for the Determination of Aspartame and its Decomposition Products

The retention behavior of aspartame and six decomposition products were evaluated as a function of added sulfonic acid ion‐pair mobile phase modifiers by HPLC. The separation of aspartame decomposition products was optimized utilizing an isocratic mobile phase of acetonitrile, monosodium phosphate buffer, and I‐heptane sulfonatc at pH 3 with UV detection at 214 nm. The effects of ion‐pair chain length and mobile phase pH on the separation and quantitation of six aspartame decomposition products were compared to traditional reversed‐phase methods. The advantage of the described method is a rapid analysis with minimal peak tailing, which is easily manipulated to maintain the desired resolution as chromatographic conditions change.