SIMULTANEOUS DETERMINATION OF ENDOGENOUS NOREPINEPHRINE AND DOPAMINE-BETA-HYDROXYLASE ACTIVITY IN BIOLOGICAL-MATERIALS BY CHEMICAL IONIZATION MASS FRAGMENTOGRAPHY

A new clean-up procedure is described for the quantitation of biogenic amines and their metabolites by gas chromatography-chemical ionization mass fragmentography. The procedure is carried out in an acidic, non-aqueous medium. The metabolites as well as the amines are extracted with greater than 92% recovery. Using a CPG-10 column, the procedure is most suitable for the purification of these amines and their metabolites from the extract. It has been applied to the simultaneous determination of endogenous norepinephrine and dopamine-β-hydroxylase (DBH) activity in rat adrenal by use of [2H2]dopamine as a substrate and [2H6]-norepinephrine as an internal standard. The quantitation limit of the DBH activity is 0.1 pmole/mg of rat adrenal per hour. © 1979.