Ultra-fast determination of caffeine, dipyrone, and acetylsalicylic acid by capillary electrophoresis with capacitively coupled contactless conductivity detection and identification of degradation products

J Chromatogr A. 2014 Jan 31:1327:149-54. doi: 10.1016/j.chroma.2013.12.048. Epub 2013 Dec 24.

Abstract

Capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4)D) was used for fast, simultaneous determination of dipyrone (DIP), caffeine (CAF), and acetylsalicylic acid (ASA). In the same run and in less than 1min, the degradation products from DIP and ASA were also detected. In addition, the usage of the CE-C(4)D system allowed, for the first time, the detection of methylamine as a degradation product of DIP. Capillary electrophoresis with electrospray mass spectrometry experiments were carried out in order to confirm the formation of methylamine. The limits of detection by CE-C(4)D were 5, 5, and 6μmolL(-1) for CAF, DIP, and ASA, respectively. The proposed method was applied to the analysis of these compounds in pharmaceutical formulations with similar results to those achieved by HPLC (p<0.05).

Keywords: Aspirin; Capillary zone electrophoresis; Hydrolysis products; Mass spectroscopy; Metamizole.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aspirin / analysis*
  • Caffeine / analysis*
  • Chromatography, High Pressure Liquid
  • Dipyrone / analysis*
  • Electric Conductivity
  • Electrophoresis, Capillary / methods
  • Hydrolysis
  • Methylamines / analysis

Substances

  • Methylamines
  • Caffeine
  • Dipyrone
  • methylamine
  • Aspirin