Abstract: A mass spectrometer system comprises an internal surface exposed to contamination and an optical sensor assembly positioned so as to monitor a reflection of optical radiation from said internal surface. A method of determining a level of contamination of an internal surface within a mass spectrometer comprises illuminating the internal surface with optical radiation, detecting optical radiation reflected from the internal surface upon illumination, determining a reflectivity value of the internal surface based on the detected optical radiation, and determining the level of contamination based on the reflectivity value.

Abstract: A sample support for a mass spectrometry system is described. The sample support comprises a substrate and a set of carbon nanotube regions adjacent to the substrate and configured to promote ionization of a sample on the sample support.