DIATHERMY KNIFE IONISATION SOURCE

摘要

A method of detecting one or more compounds, chemicals or contaminants in a substrate (2) by mass spectrometry is disclosed. A non-living substrate (2) is analysed by contacting the substrate (2) with a diathermy knife (1). An electric current is applied to the diathermy knife (1) such that the diathermy knife (1) vaporises a portion of the substrate (2). The vapour is aspirated via a sampling tube 6 pumped by a venturi pump (7) into a vacuum chamber of a mass spectrometer (9). Analyte molecules are aspirated into the vacuum chamber whereupon they impact a surface of the vacuum chamber and are ionised to form analyte ions which are then mass analysed. Alternative embodiments contemplate the use of an ultrasonic probe, a laser probe or a jet of fluid to vaporise a portion of the substrate.