Chemical Ionization Mass Spectrometry. Part I

Metabolites of Disopyramide in Rat

Abstract

During several years, we have studied drug metabolites by using mass spectrometry. The mass spectrometry gives us a lots of information for metabolites by very small amount(below 0.1 μg)of samples in the urine and bile in the very short time.However, there are several occasions in which the sample is thermally unstable or the molecular ion peak would not appear in the ordinary electron impact mass spectra(EI-MS).
We therfore prepared an ion source for chemical ionization mass spectra(CI-MS)and found that this technique is superior to the commonly used EI-MS for identification of drug metabolites.