Larson Departmental Seminar: Chemical Ionization Mass Spectrometry
Dr. Burnaby Munson University of Delaware
Date & Time:
12:15 PM - 1:20 PM
Mass spectrometry began about 100 years ago, probably with the 1913 book by Sir J. J. Thomson, “RAYS OF POSITIVE ELECTRICITY and their application to CHEMICAL ANALYSIS”. Initially, each research group made its own instrument and the emphasis was on inorganic chemistry and the determination of isotopes (existence, number, mass, abundance). In the 1940s commercial instruments became available and were used for the analysis of complex hydrocarbon mixtures from ionization by high-energy electrons at extremely low pressures (to prevent collisions between ions and molecules). Analytical organic analysis burgeoned. In the 1950s studies of gas phase ion-molecule reactions began by increasing pressure in the mass spectrometer source to allow collisions between ions and the predominant neutral molecules. Now there are many analytical techniques (with confusing acronyms) for organic and biomolecular analyses using ion-molecule reactions: CIMS, API, APCI, APPI, IMR, IMS, CID, CAD, SIFT, PTR.