THE USE OF ELECTROSPRAY-IONIZATION WITH FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE MASS-SPECTROMETRY IN THE ANALYSIS OF TRACE IMPURITIES IN A DRUG SUBSTANCE

The separation of trace impurities in cimetidine drug substance by hig h pressure liquid chromatography (HPLC) showed a series of minor compo nents. These were analysed using an on-line electrospray source connec ted to a Fourier transform ion cyclotron resonance (FT-ICR) mass spect rometer. 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 com bination of conventional analytical HPLC using 4.6 mm columns with a l ow how rate electrospray source interfaced to an FT-ICR mass spectrome ter enables structural information to be obtained on low level of low mass components.