Quadropole Mass Analyzer Four electromagnetic poles Rapidly oscillating

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Quadropole Mass Analyzer • Four electromagnetic poles • Rapidly oscillating RF potential with a

Quadropole Mass Analyzer • Four electromagnetic poles • Rapidly oscillating RF potential with a fixed DC potential • 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

Secondary Ion Mass Spectrometry “Ionization” 20 particles 10 ion - e- Ga+ Static SIMS

Secondary Ion Mass Spectrometry “Ionization” 20 particles 10 ion - e- Ga+ Static SIMS = + < 1 x 1013 ions/cm 2

Time-of-Flight Analyzer Sample +V d -V M+ Field Free Region V = stage voltage

Time-of-Flight Analyzer Sample +V d -V M+ Field Free Region V = stage voltage d = length of field free region V = voltage of detector MCP detector e = charge on an electron 1. 6 x 10 -19 C t = time for ion to reach detector m = mass v = velocity

Io n Gu TOF-SIMS Molecule-Specific Imaging n y total ion image Si+ Intensity x

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

TOF-SIMS Identification of Plasma Membrane Lipids DPPE – dipalmitoylphosphatidylethanolamine + m/z 142 -* +2

TOF-SIMS Identification of Plasma Membrane Lipids DPPE – dipalmitoylphosphatidylethanolamine + m/z 142 -* +2 H * m/z 552 m/z 682 (M+H)+ cholesterol m/z 369 m/z 385 (M-H)+

Are there Lipid Domains in the Inner Leaflet of the Membrane? Intensity 250 µm

Are there Lipid Domains in the Inner Leaflet of the Membrane? Intensity 250 µm x 250 µm Total Ion DPPE/Cholesterol Au DPPE Cholesterol DPPE + cholesterol - 552 A. G. Sostarecz; C. M. Mc. Quaw et. al. J. Am. Chem. Soc. 2004. C. M. Mc. Quaw; A. G. Sostarecz et. al. Langmuir 2005.

Multi-Isotope Imaging Mass Spectrometry Atomic Mass Images 14 N nucleus lamellipodia endothelial cell Image

Multi-Isotope Imaging Mass Spectrometry Atomic Mass Images 14 N nucleus lamellipodia endothelial cell Image from Claude Lechene Harvard Medical School

Magnetic and Electric Sector focus mass separate B = strength of magnetic field V

Magnetic and Electric Sector focus mass separate B = strength of magnetic field V = ion accelerating voltage r = radius of ion curvature m = mass of ion M = 1 -50 (change by changing B) z = charge of ion http: //www. cea. com/cai/simsinst/m_anal. htm

MIMS uses an Electrostatic and Magnetic Sector Mass Analyzer mass separate focus 14 N

MIMS uses an Electrostatic and Magnetic Sector Mass Analyzer mass separate focus 14 N ion 1 84 % 16 % Image from Claude Lechene *** MIMS analysis is performed as a collaborative project with Dr. Claude Lechene at the National Resource for Imaging Mass Spectrometry at Harvard Medical School