Degradation study of catecholamines, indole amines and some of their metabolites in different extraction media by chromatography and electrochemical detection.

Optimal conditions for the extraction from brain tissue and the simultaneous quantification of catechol and indole derivatives were determined after a systematic degradation study in water and perchloric acid. The roles of three parameters, namely temperature, presence of antioxidant agents, and time, were considered. Adrenaline, noradrenaline, dopamine, homovanillic acid, 5-hydroxytryptophan, 5-hydroxyindole acetic acid, serotonin, and epinephrine were separated by HPLC and detected electrochemically. The results indicated a great instability of the indole derivatives at an ambient temperature, in an acid medium, and in the absence of a protective agent. Therefore, when perchloric acid has to be used for deproteinization, the lowest concentration (0.1 M) is preferable. The samples have to be kept on ice, in darkness, and protected by ascorbic acid and sodium ethylenediamine tetracetate.

Toxicological analysis of phenylethylamines by high performance reversed-phase ion-pair partition thin-layer and liquid chromatographies.

A rapid and specific method was developed to identify phenylethylamines in urine. After an organic extraction at appropriate pH, reverse phase ion-pair partition chromatographies were used: a high performance thin-layer test followed by high performance liquid chromatography. The use and benefits of the procedure are described in detail and compared with other methods. In a very short time (10 min) the presence of phenylethylamine is detected on a thin-layer plate. In the case of positive result the product is then specifically identified by high performance liquid chromatography by means of a complete UV spectrum traced directly on the eluated compound. The sensitivity of the method is highly increased because the detection is operated at 215 nm.