Gas Chromatography of Sodium Cyclamate (II)

Abstract

Gas chromatographic procedure for the determination of sodium cyclamate was studied. According to recent studies, it has been reported that sodium cyclamate reacts with nitrite and produces cyclohexanol, cyclohexanone and cyclohexene. The author's experiment showed that the major product of the reaction was cyclohexyl nitrite, together with some cyclohexanol and slight cyclohexene in the presence of excess nitrite at temp. below 5°C.Using the blended liquid phase column consisting of DC-550 and DEGS (10% of each) on Gaschrom P (60/80mesh) at 60°C, carrier gas nitrogen (60ml/min) and a flame ionization detector, cyclohexyl nitrite and cyclohexanol were investigated. The results are given in Fig. 1- (C) and 2.Sodium cyclamate was determined on the basis of the cyclohexyl nitrite. The cyclohexyl nitrite was prepared by treating varying amounts of sodium cyclamate with 5ml of 10% sodium nitrite and 4ml of 10% sulfuric acid in ice water and it was extracted with 10ml of n-hexane containing 0.25 v/v% n-decane as internal standard and then injected to the Shimazu gas chromatograph.The relation between peak heights of cyclohexyl nitrite and amounts of sodium cyclamate was linear in the range of 20-600mg of the latter, and in this case, cyclohexanol did not appeared. But, when excessive amounts (>800mg) of sodium cyclamate were present, the yield of cyclohexyl nitrite diminished and that of cyclohexanol increased. The minimum limit of detection was approximately 0.1μg as sodium cyclamate.