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Atomic Absorption. Terry A. Ring Chemical Engineering University of Utah. E= -13.6 eV Z 2 /n 2. Photo absorption/emision. Atomic Absorption. Lamps are Special. Cathode with receptacle for material Vapor of Material to be analyzed Vapor Excited by plasma Light of particular wavelength.
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Atomic Absorption Terry A. Ring Chemical Engineering University of Utah
Lamps are Special • Cathode with receptacle for material • Vapor of Material to be analyzed • Vapor Excited by plasma • Light of particular wavelength
Aerosol Flow • Burner Fuel (& oxidizer) mixed with aerosol of sample • Sample asperated into burner • Flame ionizes Sample
Intensity vs Wavelength in AA • Light Source • Absorbance • Monochromatic • Detector
Analysis • Absorption of Light • Electrons are excited • Light Intensity on detector is less
Other AA’s • Flame • Spark • Arc • Plasma • Laser • X-ray
Atomic Emission Spectroscopy • Flame is used to generated Atoms with excited electrons and ions • Light is filtered in spectrometer to give Intensity vs wavelength
Spectrometer • Emitted Light • Broken into different color components • Prism • Grating
X-ray Fluorescence • Two Steps • Absorption of X-ray • Elimination of electron for k or L shell • Collapse of M shell electron to fill hole • Light emission (x-ray)
Potential X-ray Emissions • From K shell hole • K, K, K, • Zeeman Effect - 1, 2, 3 • From L shell hole • L, L, L,
Generation of X-rays • High Voltage Electrons • Electron Scattering • Electron Absorption • X-ray photo ionization
XRF • Energy-dispersive XRF • Wavelength-dispersive XRF
XRF Detectors • Energy-dispersive XRF • Semiconductor • Wavelength dispersive XRF • Scintilation Counter
XRF Analysis • Samples can be in any form • Solid • Powder • Liquid