Basic Principles of Atomic Absorption and Atomic Emission ...

1 Basic Principles of Atomic Absorption and Atomic Emission Spectroscopy 2 Source Wavelength Selector Sample Detector Signal Processor Readout P Flame Atomic Emission Spectrometer 3 Flame Atomic Emission Spectrometer 4 Emission Techniques Type Method of Atomization Radiation Source Arc sample heated in an sample electric arc (4000-5000oC) Spark sample excited in a sample high voltage spark Flame sample solution sample aspirated into a flame (1700 3200 oC) Argon sample heated in an sample plasma argon plasma (4000-6000oC) 5 Flame and Plasma Emission Spectroscopy are based upon those particles that are electronically excited in the medium. The Functions of Flame and Plasma convert the constituents of liquid sample into the vapor state. 2. To decompose the constituents into atoms or simple molecules: M+ + e- (from flame) -> M + hn 3. To electronically excite a fraction of the resulting Atomic or molecular species M -> M* Emission Spectroscopy 6 Measure the intensity of emitted radiation Emission Spectroscopy Gro und StateExc ited StateEmits Special Electromagnetic Radiation7 8 Argon Inductively Coupled Plasma as an atomization source for Emission spectroscopy 9 10 Flame techniques are limited to alkali (Li, Na, K, Cs, Rb) and some alkaline earth metals (Ca and Mg) More energetic sources are used for more elements specially transition elements sim

44 • Flame Emission -> it measures the radiation emitted by the excited atoms that is related to concentration. • Atomic Absorption -> it measures the radiation absorbed by the unexcited atoms that are determined. •Atomic absorption depends only upon the number of unexcited atoms, the absorption intensity is not directly affected by the

Tags:

  Emissions, Atomic, Absorption, Atomic absorption, Atomic emission

Information

Related search queries