Rapid estimation of trace amounts of ethylenimine by high-pressure liquid chromatography

A rapid procedure utilizing high-pressure liquid chromatography is described for determining trace quantities of ehtylenimine down to 0.01 ppm. The basis for the method is the quantitative reaction of ethyleneimine with the 1,2-naphthoquinone-4-sulphonate ion (Folin's reagent) to give 4-(1-aziridinyl)-1,2-naphthoquinone. Compared with the spectrophotometric procedure, this method provides a high degree of specificity and sensitivity. The method has been employed to determine ethylenimine in the pyrolysis products of polyethylenimine.