Xia Lian, Sun Zhiwei, Suo You-rui
Dec 9, 2009
Citations
1
Influential Citations
4
Citations
Journal
Journal of Liquid Chromatography & Related Technologies
Abstract
A simple, sensitive, and mild method for the determination of amines based on a condensation reaction with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (EDC · HCl) as the dehydrant with fluorescence detection has been developed. Amines were derivatized to their acid amides with labeling reagent 4-s(1-methyl-1H-phenanthro[9,10-d]imidazole-2-) benzoic acid (MPIBA). Studies on derivatization conditions indicated that the coupling reaction proceeded rapidly and smoothly in acetonitrile to give the corresponding sensitively fluorescent derivatives with a maximum excitation at λex 260 nm and a maximum emission at λem 446 nm. The labeled derivatives exhibited high stability and were enough to be efficiently analyzed by high-performance liquid chromatography. Identification of derivatives was carried out by online post-column mass spectrometry (LC/APCI–MS/MS) and showed an intense protonated molecular ion corresponding m/z [MH]+ under APCI in positive-ion mode. At the same time, the fluorescence properties of derivatives in various solvents were investigated. The method, in conjunction with a gradient elution, offered a baseline resolution of the common amine derivatives on a reversed-phase Eclipse XDB-C8 column. Liquid chromatography separation for the derivatized amines showed good reproducibility with acetonitrile–water as mobile phase. Detection limits calculated from 90.00 pmol to 88 fmol injection, at a signal-to-noise ratio of 3, were 10.5–53.4 fmol. Excellent linear responses were observed with coefficients of >0.9996. The established method for the determination of aliphatic amines from real wastewater was satisfactory.