DETERMINATION OF CYCLAMATE IN FOODS BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY

A simple and widely applicable method for the determination of cyclamate in foods by high performance liquid chromatography was developed. The sample was dialyzed with 0.02 N hydrochloric acid for 48 hours. Tetra-n-butylammonium bromide was added to the dialyzate, then the sample solution was adjusted to pH 4.0 approximately 5.0 and passed through a Mega Bond Elut C18 cartridge. Cyclamate was eluted with a mixture of acetonitrile-water (3:7). Cyclamate in the eluate was converted into N,N-dichlorocyclohexylamine by reaction with sodium hypochlorite; the eluate was acidified with 50% sulfuric acid, then n-hexane and sodium hypochlorite solution were added, and the mixture was shaken to form N,N-dichlorocyclohexylamine. The n-hexane layer was shaken with sodium hydrogen carbonate solution to remove free chlorine. The N,N-dichlorocyclohexylamine in the n-hexane layer was separated on a Finepak SIL C18T-5 column with a mobile phase of methanol-water (8:2) and detected at 314 nm. The recoveries of cyclamate added at the levels of 50 and 500 mug/g to various kinds of foods were 96.5 approximately 100% and 94.8 approximately 98.8%, respectively. The detection limit of cyclamate was 10 mug/g. This method seems to be very well suited for routine analysis.