title: Sensitive and specific method for the simultaneous determination of natural and synthetic catecholamines and 3,4-dihydroxyphenylglycol in microdialysis samples.
abstract: The relatively new technique of microdialysis provides new possibilities for investigating in vivo the functioning of the sympathetic nervous system. The small sample volumes obtained, however, are a great challenge for analytical chemists. We report here a HPLC method for measuring in one run both natural and synthetic catecholamines [dopamine, (nor)epinephrine, alpha-methylnorepinephrine, isoproterenol and epinine] and the intraneuronal metabolite 3,4-dihydroxyphenylglycol in small microdialysis samples after derivatization with the fluorogenic agent 1,2-diphenylethylenediamine. No prior clean-up step is necessary. N-Ethylmaleimide is necessary for preventing an inhibitory action on derivatization occurring in in vivo microdialysis samples. The method can handle large numbers of samples, is sensitive (on-column detection limits 30 to 200 fg) and reproducible (RSD 1 to 7%). Recovery characteristics of the commercial microdialysis probe used (CMA/20) were extensively investigated both in vitro and in vivo at various perfusion rates; for practical purposes a rate of 2 microl/min and sampling at 10-min intervals was found to be workable and to give good and reproducible recoveries (50 to 70%).
authors.affiliation: Cardiovascular Research Institute COEUR, Division of Internal Medicine I, University Hospital Dijkzigt/Erasmus University, Rotterdam, The Netherlands.
authors.forename: G
authors.initials: G
authors.lastname: Alberts
authors.forename: T
authors.initials: T
authors.lastname: Lameris
authors.forename: A H
authors.initials: AH
authors.lastname: van den Meiracker
authors.forename: A J
authors.initials: AJ
authors.lastname: Man in 't Veld
authors.forename: F
authors.initials: F
authors.lastname: Boomsma
mesh_terms: D000818:Animals; D002395:Catecholamines / Q000032:analysis*; D006801:Humans; D008734:Methoxyhydroxyphenylglycol / Q000031:analogs & derivatives* / Q000032:analysis; D017551:Microdialysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013552:Swine
chemical_list: D002395:Catecholamines; D008734:Methoxyhydroxyphenylglycol; C010117:3,4-dihydroxyphenylglycol