Abstract:

In order to determine aliphatic amines, a fluorescent material, 4-(1-methy-1H-phenanthro[9,10-d]imidazol-2-) benzoic acid (MPIBA), was synthesized through the derivatization of aliphatic amines at 80 ℃for 10 min in the presence of 1-ethyl-3(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC·HCl) catalyst in tetrahydrofuran solution. The maximum excitation and emission wavelengths of this stable derivative were 260 and 446 nm, respectively. The separation of these derivatized amines was achieved on a reversed-phase Eclipse XDB C8 (4.6 × 150 mm i.d., 5μm) column using a gradient elution and exhibited a good baseline resolution. The identification of aliphatic amine derivatives was carried out by post-column online APCI/MS (atmospheric pressure chemical ionization) in a positive-ion mode. Excellent linear responses were observed with a coefficient of larger than 0.9996 and a detection limit (at signal-to-noise of 3:1) of 10.5－53.4 fmol. This established method provided satisfactory results for determining amines from bean curd with odor.

Key words: HPLC, fluorescence detection, pre-column derivatization, aliphatic amines