1 / 12

http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm

http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm. http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld008.htm. Distribution Constant . Equilibrium constant Also called the partition coefficient K

presta
Download Presentation

http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htmhttp://antoine.frostburg.edu/chem/senese/101/matter/slides/sld006.htm

  2. http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld008.htmhttp://antoine.frostburg.edu/chem/senese/101/matter/slides/sld008.htm

  3. Distribution Constant • Equilibrium constant • Also called the partition coefficient • K • K = [A]s/[A]m (the ratio of the concentration of a component in the stationary phase to the concentration of that component in the mobile phase)

  4. Selectivity Factor • α (alpha) • Alpha is a measure of how well two components in a mixture will separate • α = KB/KA • By definition, component B is the component with a higher K ; therefore B prefers the stationary phase over A and will be eluted with a longer retention time. Due to this α will always be greater than 1

  5. http://antoine.frostburg.edu/chem/senese/101/matter/slides/sld009.htmhttp://antoine.frostburg.edu/chem/senese/101/matter/slides/sld009.htm

  6. http://www.unsolvedmysteries.oregonstate.edu/GCMS_05.shtml http://www.shsu.edu/%7Echm_tgc/sounds/GC-MS.mov

  7. Electron Ionization • Molecule + e- molecule+ + 2e- • Four electromagnetic poles • Rapidly oscillating field • If mass of ion and frequency of oscillation are comparable then the ion will oscillate towards the detector and be measured • A certain mass range can be selected depending on the pole diameter Quadropole Detector

  8. 20 particles 10 ion - + e- Secondary Ion Mass Spectrometry Ga+ Static SIMS = < 1 x 1013 ions/cm2

  9. Time-of-Flight Detection Scheme d -V +V M+ MCP detector Field Free Region Sample e = charge on an electron 1.6 x 10-19 C t = time for ion to reach detector m = mass v = velocity V = stage voltage d = length of field free region V = voltage of detector

  10. TOF-SIMS Molecule-Specific Imaging total ion image Ag+ Intensity Ion Gun y x 570 µm x 570 µm m/z, +ions molecule-specific image Si+ Ag+ Cu+ Si+ Cu+ copper grid affixed to silicon substrate with silver paste

  11. TOF-SIMS Identification of Plasma Membrane Lipids + - * * +2H m/z 552 m/z 184 cholesterol m/z 369 m/z 385 (M-H)+ DPPC – dipalmitoylphosphatidylcholine m/z 735 (M+H)+

  12. DPPC (M+H)+ cholesterol DPPC tailgroup cholesterol + +2H PC m/z 552 m/z 184 - cholesterol DPPC molecular ion m/z 385 molecular ion m/z 735 m/z 369 (M-OH)+ TOF-SIMS Allows for Chemical Identification of Lipid Domains Au 370 µm x 370 µm A. G. Sostarecz; C. M. McQuaw et. al. J. Am. Chem. Soc.2004.

More Related