SIMULTANEOUS MEASUREMENT OF MONOAMINES, THEIR METABOLITES AND 2,3-DIHYDROXYBENZOATE AND 2,5-DIHYDROXYBENZOATE BY HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION - APPLICATION TO RAT-BRAINDIALYSATES

A reversed-phase chromatographic method with electrochemical detection was developed for the simultaneous determination of 2,3- and 2,5-dihy droxybenzoates, indicators of in vivo hydroxyl free radical formation, monoamines (NE, DA, 5-HT) and their metabolites (MHPG, DOPAC, HVA, 3M T, 5-HIAA). Linearity was observed from 10 pg to 10 ng injected. Repro ducibility is correct (C.V. about 9%) except for 3MT and 5-HT. The lim it of detection for almost all products was about 20 pg injected on th e column. An application of this method in the study of the neurotoxic ity of high pressure oxygen in rat is described. The Limit of quantifi cation for all compounds was 5 ng/ml except for HVA (10 ng/ml). Some b asal levels DA, 5-HT, 5-HIAA, HVA, DOPAC, 3MT, 2,5-DHBA and 2,3-DHBA i n microdialysates coming from striatum of normoxic restrained rats are given. (C) 1998 Elsevier Science B.V. All rights reserved.