Determination of neotame in non-alcoholic beverage by capillary zone electrophoresis

Neotame (NEO) is a new artificial sweetener approved as a food additive in many countries. The present method for the determination of NEO in various foodstuffs is high-performance liquid chromatography (HPLC). There are no reports on the determination of NEO in foods by capillary zone electrophoresis (CZE). Therefore a simple and rapid method to determine NEO is desired for quality control.

A CZE method combined with solid phase extraction was developed for the determination of NEO in non-alcoholic beverage. The optimum separation conditions obtained were 20 mmol L(-1) sodium borate buffer, pH 8, 25 kV applied voltage, 5 s hydrodynamic injection at 30 mbar and ultraviolet detection at 191 nm. The calibration curve showed good linearity (R(2) = 1.000) in the range 0.5-100 µg mL(-1) , and the limit of detection was 0.118 µg mL(-1) . The method was successfully applied to the determination of NEO in two kinds of beverage with migration time less than 5 min, relative standard deviation (n = 3) less than 2% and recoveries ranging from 90 to 95%.

The proposed CZE method has the advantages of shorter analysis time and lower cost compared with HPLC, indicating that it may be a good alternative to the HPLC method.