A gas chromatographic method was described employing a 3.5% SE-30 siloxane polymer as the liquid phase which permitted the separation of the catecholamines and related compounds. The satisfactory separation of epinephrine, norepinephrine, dopamine, [dihydroxyphenethylamine] metanephrine and normetanephrine was achieved through the trimethyl -silylation with hexamethyldisilazane followed by the condensation with 2 -pentanone.