Separation and Determination of Catecholamines by Microchip Electrophoresis with Laser Induced Fluorescence Spectrometry and Pump-free Negative Pressure Sample Introduction

The method of microchip electrophoresis with laser induced fluorescence detection was proposed to be used in the separation and determination of catecholamines, including norepinephrine (NE), dopamine (DA) and epinephrine (E). The application of a self-made pump-free negative pressure sample introduction system made it possible to avoid the discrimination effect in sample introduction. NE, DA and E were separated completely within 1 min under the optimum working conditions, with their average migration times of 30.59, 37.23, 46.43 s and values of RSD′s (n=7) of 1.10%, 1.28%, 0.45% respectively. Linearity ranges found were 0.3-5.0 mg·L-1 (for NE and DA) and 0.05-4.0 mg·L-1 (for E), with detection limits (3S/N) of 30, 30, 10 μg·L-1 respectively.