Abstract
Sodium N-cyclohexylsulfamate (Sodium Cyclamate) forms cyclohexylamine by hydrolysis with hydrochloric acid with addition of hydrogen peroxide and the product colors with quinhydrone. The coloration differs according to whether an aqueous solution or organic solvent was used in the reaction. This was utilized in devising methods A and B for colorimetric determination of sodium N-cyclohexylsulfamate according to its concentration. Method A: Hydrogen peroxide solution and hydrochloric acid are added to the test solution (containing 1-10mg./ml.), the mixture is heated in a boiling water bath for 2 hours, cooled, and neutralized with sodium hydroxide. Hydrogen peroxide is decomposed with an excess of manganese dioxide, the mixture is centrifuged, and the supernatant is adjusted to pH 9.0 with a buffer solution. Quinhydrone reagent is added to it, the mixure is warmed, acidified with acetic acid, and extracted with chloroform. The absorbancy of this extract solution is read at 355mμ. Method B: Hydrogen peroxide solution and hydrochloric acid are added to the test solution (containing 50-600γ/ml.), the mixture is heated in a boiling water bath for 1.5 hours, cooled, and neutralized with sodium hydroxide. This is adjusted to pH 12.0 with a buffer solution and extracted with chloroform. Ethanol and quinhydrone reagent are added to the extract solution, the mixture is warmed, and its absorbancy is read at 495mμ.
