Determination of Methacholine Chloride by Ion-Pair High-Pressure Liquid Chromatography

Abstract

A method of analysis of methacholine chloride is presented, which is adaptable to other choline esters. The method uses ion-pair high-pressure liquid chromatography. Using 1-heptane sulfonic acid optically transparent at low UV wavelengths as the specific ion-pair, it was possible to assay for a specific choline ester using ultraviolet detection at 210 nm without interference by hydrolytic by-products. The method can be used to provide quality control and stability data on methacholine chloride in 0.9% sodium chloride solutions.