Abstract
Ethyleneglycol is oxidized to formaldehyde and determined colorimetrically by the reaction with either chromotropic acid or 3-methyl-2-benzothiazolinone hydrazone. It was found that the oxidatior of ethyleneglycol with potassium permanganate-sul.furic acid was accelerated by acetaldehyde-ammonia ([CH3 CH(NH2)OH]3). Based on this fact, a procedure for the determination of ethyleneglycol was established To 1.0ml of the test solution containing (1040) of ethyleneglycol, add 0.2ml of 0.05w/v% ace. taldehyde-ammonia solution, 0.1ml of 0.25M sulfuric acid, and 0.1ml of 1.20% potassium permanganate solution. Allow the mixture to stand at room tem. perature for 50min. Add 0.1ml of 20% sodiurr sulfite solution to reduce excessive permanganate and 0.2ml of 2% aqueous chromotropic acid solution Add slowly 4ml of 75% sulfuric acid. Heat the mixture in a boiling water bath for 10min. Upon cooling to room temperature, measure the absorbance at 575nm against the reagent blank. The calibratior curve was linear in a range of (1040)μg ethylenegly. col/ml, the coefficient of variation being 4.2%. Me thanol and glycerol seriously yielded a positive interfer ence.
