Chemical Ionization Studies with a DuPont 21-490 Analytical Mass Spectrometer

Abstract : A DuPont 21-490 analytical mass spectrometer has been modified to operate as a chemical ionization instrument. The basic requirements of a CIMS system and details of the actual mechanical, electrical and other changes have been described. Propane and a mixture of propane/benzene has been used to demonstrate the performance of the system. A method has been designed to estimate the ion-source pressure. A series of selected ketones have been used to obtain their chemical ionization mass spectra with propane reagent gas.