Abstract: A method to determine aspartame in diet coke by high performance liquid chromatography on a titania column was described in this paper. The samples were separated on a titania Sachtopore-RP column (250 mm×4.6 mm, 5 μm at 70 ℃ using 15 mmol/L ammonium phosphate buffer ((NH4)2HPO4:NH4H2PO4=6:4) added with 10 mmol/L ammonium fluoride and methanol in the ratio of 70 to 30 as mobile phase. The flow rate was 1 mL/min and the detection wavelength was 217 nm. The linear range of the method was 10－2500 μg/mL with a Detection limit of 0.08 μg/mL. The recoveries of the method were between 92.5% and 97.4%. The relative standard deviation of the method was less than 0.72%. The method is simple, fast, accurate and precise and may be used in the determination of aspartame in drinks.

Key words: aspartame, titania, RP-HPLC, sugarless coke