Jacox & Meckstroth
Mass spectrometer for chemical ionization and electron impact ionization operation
 A mass spectrometer instrument for chemical analysis. An instrument of this invention is capable of performing cyclic operation repetitively and automatically. Each operation cycle consists of at least one chemical ionization operation mode and one venting operation mode. Furthermore, an instrument of this invention is capable of performing cyclic operation which includes multiple chemical ionization operation modes in which each of a plurality of reagent gases is individually employed for each chemical ionization operation mode. Electron impact ionization can also be conducted during each venting operation mode should it be desired. Positive ion and negative ion spectra are also recorded simultaneously which further improves the efficiency of the cyclic operation. 
H
H01J
inventional
Cherng
Chang