Identification of 3,4-dimethoxyphenethylamine from schizophrenic urine by mass spectrometry.

Abstract

THE occurrence of the “pink spot” in the urine of schizophrenics was first reported by Friedhoff and van Winkle1, who tentatively identified the substance as 3,4-dimethoxyphenethylamine (3,4-DMPEA). Subsequent interest in this amine is linked to the possibility that its formation may result from an aberration in the metabolism of the endogenous amine, dopamine, as either a resultant or aetiological factor in mental disorders2. Reports of both confirmatory3–7 and conflicting8–14 nature have appeared with respect to the identity and origin of the “pink spot”15,16. The methods which have been used to isolate and identify the “pink spot”, solvent extraction, ion-exchange chromatography, paper and thin-layer chromatography, counter-current distribution and various colour reactions, have not provided unequivocal identification. Much of the controversy originates from the non-specificity of chromatographic separation and the complexity of amines present in human urine. Indeed, several “pink spot” occur in urine extracts which are isographic in one or more of the solvent systems used to isolate the “pink spot”.