DETERMINATION OF DIMETHYLAMINE AND OTHER LOW-MOLECULAR-MASS AMINES USING CAPILLARY-ELECTROPHORESIS WITH LASER-INDUCED FLUORESCENCE DETECTION

The potential of capillary electrophoresis (CE) with laser-induced flu orescence (LIF) detection for the separation and determination of dime thylamine (DMA) and other low-molecular-mass amines involving precolum n derivatization with fluorescein isothiocyanate isomer I(FITC) was in vestigated. Different variables that affect derivatization (pH, FITC c oncentration, reaction time and temperature) and separation (buffer co ncentration, addition of various organic modifiers, applied voltage an d length of capillary) were studied. The linearity, reproducibility an d reliability of the method were evaluated. The estimated instrumental detection limit for a 2-s pressure injection of the FITC-DMA derivati ve was 50 pg/ml (10(-9) M), using LIF detection with excitation and em ission wavelengths of 488 nm and 520 nm, respectively. However, for pr actical reasons, a minimum of 5 ng/ml DMA should be subjected to the d erivatization. The applicability of the described method to the extrac t of atmospheric aerosol samples was demonstrated. (C) 1998 Elsevier S cience B.V. All rights reserved.