Gas chromatographic chemical ionization-mass fragmentometric assay of catecholamines in the brain.

A method for gas chromatographic chemical ionization-mass fragmentometric assay of tissue catecholamines is described. Catecholamines were extracted by HClO4, absorbed to aluminum oxide and eluted by acetic acid. Pentafluoropropionic derivatives were made and injected into a gas chromatograph-mass spectrometer equipped with a chemical ionization device. The method was found to be very sensitive and results were reproducible. Epinephrine and norepinephrine could be assayed without interference from each other because of the differences of m/e numbers. Results of dopamine and norepinephrine analyses on human autopsy brain specimens were consistent with those reported in the literature using different methods. Epinephrine in small amounts could be detected in most of the cases analyzed, being highest in amount in the hypothalamus. The results suggest that epinephrine may be acting as a neurotransmitter in certain areas of the human brain.