A process for the fluorimetric determination of catecholamines and / or their metabolites, as well as device and a reagent for carrying out the method

摘要

Determination of analyte(s) (I) selected from catecholamines and/or their metabolites in a biological sample comprises inducing fluorescence in (I), after pretreatment, using a fluorescence inducing reagent (II). The fluorescent prod. is then separated by liq. chromatography and analysed. The novelty is that a predetermined amt. of maleimide (III) is added before the sample is rendered fluorescent. Alternatively, (i) in the pretreatment step the sample is added to a sample vessel to which a predetermined amt. of (III) has been added and mixed with a solvent; (ii) (III) in solid form and a solvent for (III) are prepd. separately then mixed before the sample is rendered fluorescent; or (iii) (III) is added during prepn. of the sample for fluorescence induction. Appts. for the determn. is claimed, comprising a device for delivery of a predetermined amt. of sample, connected to a pretreatment device; appts. for contacting the pretreated sample with (II); a chromatography column for adsorption and sepn. of the fluorescent prod.; and a fluorescent intensity detector; where a predetermined amt. of (III) is supplied to the sample delivery device or the pretreatment device. Pref. a processor is included, to calculate, store and display the fluorescent intensity. Also claimed is a reagent for the determn., including solid (III) and a solvent for (III), which are mixed before use. USE/ADVANTAGE - The process is used e.g. for determn. of very low concns. of norepinephrine, epinephrine or dopamine in urine, blood or spinal fluid. Addn. of (III) prevents other components of the sample from interfering with the fluorescent peaks of (I). (III) reacts with thiol cpds. and aminoacids in body fluids, preventing these cpds. from reacting with (II). More accurate results are then obtd.