Abstract:

Aliphatic amines exist widely in nature. Therefore, quick and precise determination of aliphatic amines is of great significance. A simple and highly sensitive method based on the derivatization of aliphatic amines utilizing 1,2-benzo-3,4-dihydrocarbazole-9-acetic acid (BCAA) as the novel pre-column derivatization reagent followed by high performance liquid chromatography with fluorescence detection and online mass spectrometric identification was developed. Optimum derivatization was obtained by the reaction of aliphatic amines with BCAA at 50 ℃ for 15 min in the presence of 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDAC) in acetonitrile solvent. The condition of derivatization was mild and the yield of derivative each aliphatic amine was higher than 94%. Derivatives were sufficiently stable to be efficiently analyzed by high performance chromatography without pretreatment. On a reversed-phase BDS-C18 column, twelve aliphatic amine derivatives (C1-C12) were separated under gradient elution with baseline resolution. The precise determining aliphatic amines from soil and wastewater samples was obtained by post-column online mass spectrometric identification with atmospheric pressure chemical ionization(APIC) source under positive mode detection. The established method exhibited excellent reproducibility and recovery. Linear responses were observed with coefficients over 0.9993. The detection limits (at signal-to-noise ratio of 3∶1) were 12-28 fmol.

Key words: aliphatic amines , fluorescence detection, pre-column derivatization, high performance liquid chromatography-mass spectrometry