Studies on aminophylline disposition I. A rapid and sensitive HPLC assay for ethylenediamine in plasma and urine.

A simple and rapid assay for ethylenediamine in plasma and urine is described. Ethylenediamine is treated with m-toluoyl chloride, yielding its N,N'-di(m-toluoyl) derivative, which is extracted into dichloromethane and assayed by reversed-phase high pressure liquid chromatography (HPLC) with u.v. detection. Quantitation is achieved with reference to the corresponding derivative of cadaverine as internal standard. The assay is reproducible, and the lower limit of detection is 0.05 microgram ml-1. Calibration curves in plasma and urine are linear over the concentration range 0.05-100 micrograms ml-1. The assay has been applied to the analysis of ethylenediamine in plasma and urine following the administration of aminophylline orally and intravenously to a volunteer.