The use of electrospray ionization with Fourier transform ion cyclotron resonance mass spectrometry in the analysis of trace impurities in a drug substance

Abstract

AbstractThe separation of trace impurities in cimetidine drug substance by high pressure liquid chromatography (HPLC) showed a series of minor components. These were analysed using an on‐line electrospray source connected to a Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometer. Working typically with a resolution of 10 000–20 000 accurate mass measurement of the components confirmed their empirical formulae to generally better than 5 ppm accuracy. This work shows that the combination of conventional analytical HPLC using 4.6 mm columns with a low flow rate electrospray source interfaced to an FT‐ICR mass spectrometer enables structural information to be obtained on low levels of low mass components.