Characterization of the Retention of Artificial Sweeteners by Hydrophilic Interaction Liquid Chromatography

The aim of this work was to study the chromatographic behavior of polar artificial sweeteners on three hydrophilic interaction liquid chromatography (HILIC) columns: Kinetex HILIC (unbounded silica, core shell), ZIC HILIC (sulfoalkylbetain) and TSKgel Amide-80 (amide). The studied analytes were dipeptides (aspartame, neotame, advantame, alitame), sulfamates (acesulfame, saccharin, cyclamate), and sugars (sucralose, neohesperidin dihydrochalcone). Critical parameters such as the mobile phase pH, buffer concentration, column temperature, and organic modifier were studied for the investigation of the retention mechanism. Partition and adsorption models were also used. The retention mechanism of dipeptides seems to be partition for the aqueous layer and weak electrostatic interactions or hydrogen bonds. For the sulfamates, on Kinetex and ZIC HILIC columns, it is likely that partitioning to the aqueous layer is combined with the ERLIC phenomena at pH 5.5. For the TSKgel Amide, the partition and the hydrogen bonds formed between the analytes and carbamoyl groups of the stationary phase play an important role in the retention mechanism. For sucralose, partition seems to be the predominant mechanism in every column, while, for neohesperidin dihydrochalcone, both partition to aqueous layer and hydrogen bonding seems to contribute to the retention. This is also the first report of a method for the chromatographic determination of advantame, a new sweetener.