Gas chromatographic estimation of homovanillic acid in serum of normals and psychotic patients.

Homovanillic acid is extracted from 0.5 ml serum with ethyl acetate at acidic pH, and its pentafluoropropionic anhydride and hexafluoroisopropanol derivative injected into a 3% SE-30 column at 140 degrees C, fitted with an electron capture detector. In a group of normal volunteers (n = 42) a mean value of 62+/-45 mug/l was found. The distribution of the serum concentrations was found to be bimodal. Using the same procedure for the homovanillic acid estimation in cerebrospinal fluid (CSF), mean values of 73.0+/-41 mug/l serum and 68+/-36 mug/l CSF were found for a group of 22 untreated patients with paranoid-hallucinatory syndrome. After treatment with neuroleptics, for 1 week to 1 month, the homovanillic acid concentration increased significantly only in the CSF. By the procedure described, other acidic metabolites of biogenic amines are extracted together with homovanillic acid and can also be estimated in the same sample.