Rapid and sensitive determination of tryptophan, serotonin and psychoactive tryptamines by thin-layer chromatography/fluorescence detection

A rapid, sensitive and selective method for the determination of tryptophan (Trp), serotonin (5-HT) and psychoactive tryptamines (PATs) by thin-layer chromatography (TLC) with fluorescence detection is proposed. These compounds form fluorophores on the developing plate by heating after spraying with sodium hypochlorite, hydrogen peroxide or potassium hexacyanoferrate(III)-sodium hydroxide reagent. Fluorescent spots (vivid blue) were observed by irradiation with ultraviolet light (365 nm). The detection limits of Trp, 5-HT and PATs were in the range from 0.01 μg to 0.06 μg. This method was effectively applied to the detection of confiscated PAT powder and PAT in abusers’ urine samples.