Spectrofluorimetric determination of 5-hydroxyindoles with benzylamine or 3,4-dimethoxybenzylamine as a selective fluorogenic reagent.
A spectrofluorimetric method has been developed for the sensitive and selective determination of 5-hydroxyindoles; the method is based on the reaction of 5-hydroxyindoles in a weakly alkaline solution (pH 9.0) with aromatic methylamines in the presence of potassium hexacyanoferrate(III) and dimethyl sulphoxide; the compounds produced fluoresce intensely in an alkaline solution (pH 11-12). Of the eight aromatic methylamines tested, benzylamine and 3,4-dimethoxybenzylamine were found to be the most favourable fluorogenic reagents in terms of sensitivity and reactivity. The methods with benzylamine and 3,4-dimethoxybenzylamine permit the determination of 5-hydroxyindoles at concentrations as low as 22-72 pmol ml-1 and 1.0-2.4 nmol ml-1, respectively.
Ishida
J
J
Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Yamaguchi
M
M
Nakamura
M
M
D001596:Benzylamines; D005456:Fluorescent Dyes; D007211:Indoles / Q000032:analysis*; D013050:Spectrometry, Fluorescence / Q000379:methods*
D001596:Benzylamines; D005456:Fluorescent Dyes; D007211:Indoles; C069986:3,4-dimethoxybenzylamine