Differentiation of the formaldehyde-induced fluorescent products of noradrenaline and dopamine by microspectrofluorometry.
The influence of concentration of dopamine and noradrenaline on the spectral characteristics of their formaldehyde-induced fluorophore, together with the influence of duration of reaction with formaldehyde, has been investigated in a model system. No substantial differences between fluorescence spectra of the amine fluorophores were observed. Accordingly, the influence of hydrochloric acid and ammonia vapours on the fluorophores was investigated. A shift to shorter wavelengths in the excitation maximum of each fluorophore was observed after a brief exposure to hydrochloric acid vapour; more prolonged exposure resulted in a pronounced shift back to longer wavelengths in the case of noradrenaline but no substantial change was observed with dopamine. Brief exposure to hydrochloric acid vapour resulted in a substantial increase in the rate of fading of the noradrenaline fluorophore on exposure to exciting radiation. It is suggested that this offers a convenient way of differentiating the amines.
D004298:Dopamine / Q000032:analysis*; D005557:Formaldehyde; D007202:Indicators and Reagents; D008832:Microchemistry; D009638:Norepinephrine / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods
D007202:Indicators and Reagents; D005557:Formaldehyde; D004298:Dopamine; D009638:Norepinephrine