Determination of synthetic pharmaceuticals in phytotherapeutics by capillary zone electrophoresis with contactless conductivity detection (CZE-C~4D)

摘要

In this work, a method for simultaneous determination of amfepramone, fenproporex, sibutramine and fluoxetine was developed by capillary zone electrophoresis with capacitively coupled contactless conductivity detection (C~4D) using a homemade capillary electrophoretic system. The optimized conditions for the separation of the pharmaceuticals by CZE were as follows: 50mmol L~(-1) phosphate buffer (pH 5.0) in 50/50 (v/v) mixture of water/acetonitrile as the working electrolyte, 15kV separation voltage, 25°C separation temperature, hydrodynamic injection by gravity using 20cm injection height and 60s injection time. The detection by C~4D was carried out by using a homemade detector, which employs a sinusoidal wave generator operating at 600kHz frequency and 2V_(pp) wave amplitude. The optimized and validated CZE-C~4D method was applied for the determination of the studied pharmaceuticals as adulterants in phytotherapeutic formulations commercialized in Brazil for slimming purposes.