Microspectrofluorometric studies on the formaldehyde-induced reaction product of 5-hydroxytryptamine

A new model incorporating Sephadex G-25 as an inert carrier has been developed for studying the reaction between biogenic amines and formaldehyde vapour. Both the fluorescence yield and the spectral characteristics of the 5-HT formaldehyde reaction product are influenced appreciably by the relative humidity at which paraformaldehyde is equilibrated, the duration of the reaction, the glycine concentration and pH of the suspending solution and the duration of exposure to ultraviolet light. It is concluded that care should be exercised in attempting to identify or quantify 5-HT on the basis of microspectrofluorometric analysis.