IN-VIVO MONITORING OF EXTRACELLULAR NORADRENALINE AND GLUTAMATE FROM RAT-BRAIN CORTEX WITH 2-MIN MICRODIALYSIS SAMPLING USING CAPILLARY ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION

The measurement of neurotransmitters by capillary electrophoresis (CE) has emerged as a reliable and sensitive method for microdialysis samp le analysis. This paper describes a method which employs laser-induced fluorescence detection (LIFD) of catecholamines and excitatory amino acid derivatives formed after reaction with naphthalene-2,3 -dicarboxa ldehyde. On-line derivatization of very small volumes of microdialysis samples (500 nl) is developed before two off-line analyses (total run time of less than 10 min) are performed to detect derivatives of cate cholamines and excitatory amino acids formed in each sample. High micr odialysis temporal resolution is reached (2-min fractions) for the sim ultaneous monitoring of noradrenaline (NA) and glutamate concentration s from rat brain cortex microdialysates. The system performance is eva luated and pharmacological characterization of the determination of NA in cortical dialysates by CE-LIFD is reported.