Abstract: This is an ion-producing source having a distinct chemical ionization configuration and a distinct electron impact configuration. In this source, a hollow chamber including an ion source and a source of sample molecules receives a hollow, slidable cylindrical member having a chemical ionization chamber within it. Orifices in the chamber and the cylindrical member connect the chemical ionization source chamber to the electron source and to the sample molecule source when the cylindrical member is pulled to one position. When the cylindrical member is pulled to another position, the slidable cylindrical member and the inside walls of the chamber define the ionization region to which the electron source and the sample molecule source are directly connected. By moving the cylindrical member, the ionization source can be changed from a chemical ionization source to an electron impact source.

Abstract: This is an ion-producing source having a distinct chemical ionization configuration and a distinct electron impact configuration. In this source, a hollow chamber including an ion source and a source of sample molecules receives a hollow, slidable cylindrical member having a chemical ionization chamber within it. Orifices in the chamber and the cylindrical member connect the chemical ionization source chamber to the electron source and to the sample molecule source when the cylindrical member is pulled to one position. When the cylindrical member is pulled to another position, the slidable cylindrical member and the inside walls of the chamber define the ionization region to which the electron source and the sample molecule source are directly connected. By moving the cylindrical member, the ionization source can be changed from a chemical ionization source to an electron impact source.