Determination of diethanolamine and morpholine in systems containing copper(II) using liquid chromatography

Abstract

A method is described for determining 2,2′-iminobisethanol (diethanolamine) and tetrahydro-1,4-isoxazin (morpholine) in a system containing copper(II). By using a more powerful complex-forming agent, copper(II) is removed from the sample, and the compounds to be determined are extracted with acid and separated on a strongly acidic sulphonated cation-exchange column with phosphate buffer as the mobile phase. The relative error of the method is less than 5%, the detection limit being 20 p.p.m. for each amine.