tailieunhanh - Mass Spectrometry 1

Mass Spectrometry (. MS or mass spec) – a method of separating and analyzing ions by their mass-to-charge ratio MS does not involve a specific region of the electromagnetic spectrum (because it is not directly interested in the energies of emitted photons, electronic or vibrational transitions, nuclear spin transitions, etc ) | VILLANOVA UNIVERSITY Mass Spectrometry and Related Techniques 1 Lecture Date February 25th 2008 Ion and Particle Spectrometry 1 - Outline Atomic and Molecular Mass Spectrometry - Skoog et al. Chapter 11 atomic and Chapter 20 Molecular . - Cazes Chapter 14 1 Mass Spectrometry Mass Spectrometry . MS or mass spec - a method of separating and analyzing ions by their mass-to-charge ratio MS does not involve a specific region of the electromagnetic spectrum because it is not directly interested in the energies of emitted photons electronic or vibrational transitions nuclear spin transitions etc. Ion abundance Ion Ion Ion m z Up to m z 100000 General Notes on Atomic and Molecular Mass Helpful units and conversions - 1 amu 1 Da 1 12 the mass of a neutral 12C atom. - 1 kDa 1000 amu Atomic weights of other elements are defined by comparison. Mass-to-charge ratio m z the ratio of the mass of an ion m to its charge z Molecular ion an ion consisting of essentially the whole molecule 2 Mass Spectrometers A block diagram of a generic mass spectrometer Ionization Source Mass Analyzer Ionization Sources Electron Ionization EI Chemical Ionization CI APCI Photo-ionization APPI Electrospray ESI Matrix-assisted Laser Desorption MALDI Field Desorption FD Plasma Desorption PD Fast atom bombardment FAB Gas Phase Desorption High-temperature Plasma ICP Ionization Source Mass Analyzer Detector See also Table 20-1 in Skoog et al.