AROMATIC GLYCINONITRILES AND METHYLAMINES AS PRECOLUMN FLUORESCENCE DERIVATIZATION REAGENTS FOR CATECHOLAMINES

The reactivity of some catecholamines with aromatic glycinonitriles (A GN) (four species) and aromatic methylamines (AMA) (five species) was investigated in detail, to find pre-column fluorescence derivatization reagents for catecholamines. Of the nine reagents tested, 2-phenylgly cinonitrile (PGN) and benzylamine (BA) were shown to be the best reage nts in terms of selectivity and sensitivity, The reagents react select ively with catecholamines under mild conditions in the presence of amm onium molybdate and sodium periodate for PGN and potassium hexacyanofe rrate(III) for BA to give fluorescent derivatives. The derivatives of four catecholamines (epinephrine (E), norepinephrine (NE), dopamine (D A) and isoproterenol (IF)) could be separated within 13 min by reverse d-phase liquid chromatography with isocratic elution and measured fluo rimetrically. The detection limits (signal-to-noise ratio=3) are in th e range 5.2-11.0 fmol for PGN and 1.6-100 fmol for BA in a 50 mu l inj ection volume. The liquid chromatographic (LC) methods with PGN and BA were successfully applied to the determination of some catecholamines in human urine.