New antioxidant mixture for long term stability of serotonin, dopamine and their metabolites in automated microbore liquid chromatography with dual electrochemical detection.
An automated microbore liquid chromatographic assay with dual electrochemical detection is described for the determination of serotonin, dopamine and their metabolites, 5-hydroxyindoleacetic acid, 3,4-dihydroxyphenylacetic acid and homovanillic acid. Due to the chemical instability of the compounds, the addition of an antioxidant is required for automated analysis over a long period of time (e.g., 20 h). Therefore, the time stability of these substances was tested with different antioxidants. The stability for serotonin and 5-hydroxyindoleacetic acid was poor in acidic medium containing Na2EDTA but could greatly be improved by the addition of L-cysteine and ascorbic acid. Using this assay, the neurotransmitters and their metabolites could easily be determined in microdialysates obtained from different rat brain areas.
Thorré
K
K
Department of Pharmaceutical Chemistry and Drug Analysis, Vrije Universiteit Brussel, Brussels, Belgium.
Pravda
M
M
Sarre
S
S
Ebinger
G
G
Michotte
Y
Y
D015102:3,4-Dihydroxyphenylacetic Acid / Q000032:analysis; D000975:Antioxidants; D001205:Ascorbic Acid; D002853:Chromatography, Liquid; D003545:Cysteine; D004298:Dopamine / Q000032:analysis* / Q000378:metabolism; D004355:Drug Stability; D004492:Edetic Acid; D004563:Electrochemistry; D006719:Homovanillic Acid / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D006897:Hydroxyindoleacetic Acid / Q000032:analysis; D017551:Microdialysis; D010084:Oxidation-Reduction; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012701:Serotonin / Q000032:analysis* / Q000378:metabolism
D000975:Antioxidants; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004492:Edetic Acid; D003545:Cysteine; D001205:Ascorbic Acid; D004298:Dopamine; D006719:Homovanillic Acid