ANALYSIS OF HUMAN CEREBROSPINAL-FLUID BY CAPILLARY ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION

Capillary electrophoresis with laser-induced fluorescence detection is used to analyze 10 mu L samples of human cerebrospinal fluid. Primary amine-containing compounds in untreated cerebrospinal fluid are label ed with 3-(4-carboxybenzoyl)-2-quinolinecarboxaldehyde prior to analys is, producing fluorescent isoindoles. Electropherograms containing app roximately 50 peaks are obtained in less than 35 min from cerebrospina l fluid samples. Ten peaks in the electropherograms have been identifi ed and quantitated: arginine, glutamine, threonine, valine, gamma-amin o-n-butyric acid, serine, alanine, glycine, glutamic acid, and asparti c acid. Detection limits for these 10 amino acids range from 0.29 nM f or gamma-amino-n-butyric acid to 100 nM for threonine, and separation efficiencies as high as 190 000 theoretical plates are obtained for th ese analytes. Electropherograms of cerebrospinal fluid samples from pa tients with Alzheirner's disease and from children with different neur ological disorders are compared to those of healthy controls. Differen ces in individual amino acid levels are observed between the patient g roups, and these differences appear to be disease and age related. The se results indicate that analysis of cerebrospinal fluid by capillary electrophoresis will be useful as a selective, rapid, and sensitive to ol for both diagnosis of central nervous system disorders and for stud y of the mechanisms of these disorders.