Indirect Determination of Sodium Cyclamate in White Spirit by Flame Atomic Absorption Spectrometry

A method for indirect determination of sodium cyclamate in white spirit by FAAS was studied and reported in this paper.Sodium cyclamate was extracted with ether from acidified white spirit sample.The extract was evaporated to eliminate ether and nitrified with conc.HNO3 in water bath at 100 ℃.In the course of nitration,sulfonate was displaced from the molecule of sodium cyclamate to give SO2-4 which was precipitated as BaSO4 from the solution with suspension of barium chromate.Chromate liberated in the reaction was then determined by FAAS,and the amount of chromium(Ⅵ) found was converted into contents of sodium cyclamate.Linear relationship between absorbance and mass concentration of sodium cyclamate was obtained in the range within 0.35 g·L-1,corresponding to the linear regression equation of A=0.301 ρ甜+0.018.Detection limit (3S/N) of the method was 0.02 g·L-1.Tests for precision were made by addition of 0.060,0.250,0.500 g·L-1 of the sodium cyclamate standard solution to blank wine samples,and values of RSD′s obtained were 8.93%,3.44%,3.63%.Values of recovery were found in the range of 86.7%-105.0%.