Categories of exhibits
EI/CI moving belt source
Exhibit no. 197
Moving belt is a transport type LC/MS interface developed in the late 1970s. It consisted of an endless belt, which received effluent from an LC column. After evaporating the solvent, the analytes were desorbed from the belt and ionized. The moving belt interface made it possible to combine liquid chromatography with EI, CI, and FAB mass spectrometry.
The exhibit is an EI/CI ion source assembly for a moving belt interface, which was used with a sector mass spectrometer ZAB EQ (VG Analytical, Ltd., 1986). It consists of a round mounting plate with a supporting shaft. Copper clad steel springs around the circumference of the plate mated with feedthroughs in the source housing cover plate. A block plate at the upper end of the shaft holds the ion chamber, plates, and slits separated by ceramic spacers. The filament is mounted on the side of the chamber, while the electron trap and repeller are located inside the chamber. A length of 0.006" bore stainless steel tubing coupled to a glass capillary was used to deliver CI gas. Since the probe (moving belt shaft) tip contained a platinum coil heater for evaporating the sample into the ion chamber, the ion source assembly also contains contacts for electrical connections to the probe heater.
