Abstract
1 A gas chromatographic method using electron capture detection is described for the estimation of those catecholamines and their metabolites which possess one or two free alcoholic hydroxyl groups. It is based on acetylation of phenolic hydroxyl and primary and secondary amino groups in aqueous solution, extraction into a water immiscible solvent and esterification of alcoholic hydroxyl groups with heptafluorobutyric anhydride. 2 The method has been successfully applied to the detection and estimation of free 4-hydroxy-3-methoxyphenylethylene glycol (MOPEG) and free 3,4-dihydroxyphenylethylene glycol (DOPEG) in hypothalamic brain tissue. 3 Although it was possible to measure noradrenaline and normetanephrine by the same method in pure solution, crude tissue extracts could not be used, despite their suitability for estimating the glycol metabolites.