Atomic Absorption Terry A. Ring Chemical Engineering University

Atomic Absorption Terry A. Ring Chemical Engineering University of Utah

E -13.6 eV Z2/n2

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

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

Graphite furnace AA

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 (xray)

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 Wavelengthdispersive XRF

XRF Detectors Energy-dispersive XRF – Semiconductor Wavelength dispersive XRF – Scintilation Counter

XRF Analysis Samples can be in any form – Solid – Powder – Liquid