Quantitative analysis of ethylenediamine in plasma by capillary column gas chromatography

A specific and sensitive method for the determination of ethylenediamine in human plasma is described. The aqueous sample is treated with m-toluoyl chloride, yielding the N,N′-bis(m-toluoyl) derivative of the diamine, which is extracted into dichloromethane and quantitated after “on column” methylation by capillary gas liquid chromatography with alkali flame ionization detection. The corresponding derivative of putrescine serves as internal standard. The assay is reproducible and calibration curves are linear over the concentration range 0.05 to 10 μg · ml−1. The lower detection limit is about 10 ng · ml−1. The structures of the compounds of interest eluting from the capillary column are examined by gas liquid chromatography/mass spectrometry. The assay has been applied to the analysis of ethylenediamine in plasma following the administration of aminophylline and ethylenediamine in a cross-over study to patients with bronchopulmonary diseases. The method also proves suitable for measuring other primary and secondary amines and diamines in aqueous solutions by gas liquid chromatography.