Gratings, atomic spectroscopy

The besl isolation of radiant energy can he achieved with flame spectrometers that incorporate either a prism sir grating monochromator, those with prisms having variable gauged entrance and exii slits. Both these spectrometers provide a continuous selection of wavelengths with resolving power sufficient lo separate completely most of the easily excited emission lines, and afford freedom from scattered radiation sufficient lo minimize interferences. Fused silica or quartz optical components are necessary to permit measurements in Ihe ultraviolet portion of the spectrum below 350 nanometers Sec also Analysis (Chemical) Atomic Spectroscopy Photometers and Spectra Instruments. 

Felkel, H. L., Jr., "Evaluation of imaging detector coupled to an echelle grating spectrometer for atomic spectroscopy", Ph.D. Thesis, Purdue University, 1978. 

The author gratefully acknowledges the kind permission to use some figures from other sources of publication figures reprinted from Spectrochim-ica Acta Part B, Spectrochimica Acta Review, Progress in Analytical Atomic Spectroscopy, and Thermochimica Acta with kind permission from Elsevier Science, Amsterdam, the Netherlands figures reprinted from the Proceedings... 

Simultaneous multicomponent determinations, 361 Sine waves, 33, 34, 508,956 mathematical description, 135 superposition. 137 Single-beam computerized spectrophotometers, 358 grating instruments, 357 instruments, 240, 241, 351 for atomic spectroscopy, 240 efl ect of mismatched cells, 343 for molecular absorption measurements, 351 advantages, 358 Singlet state, 216, 400-402,411 excited, 216,400,401,405 Size distributions, measuring, 951. 955, 961... 

In Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), a gaseous, solid (as fine particles), or liquid (as an aerosol) sample is directed into the center of a gaseous plasma. The sample is vaporized, atomized, and partially ionized in the plasma. Atoms and ions are excited and emit light at characteristic wavelengths in the ultraviolet or visible region of the spectrum. The emission line intensities are proportional to the concentration of each element in the sample. A grating spectrometer is used for either simultaneous or sequential multielement analysis. The concentration of each element is determined from measured intensities via calibration with standards. 

An atomic site in a rare-gas matrix is, of course, of microscopic size. However, atoms in a beam can be excited by laser spectroscopy to extremely high n values if such a beam is pointed at a metallic grating made up of micrometre-size slits, then a cut-off will be observed in the maximum n value of the atoms which can fly through the apertures unimpeded. Such an experiment has been reported by Fabre [37] and coworkers in Paris. While it is experimentally very challenging to realise, the principle of this... 

Most instruments constructed for atomic flame emission and atomic absorption spectroscopy have dispersions in the range of 15-35 A/mm. For example, the Perkin-Elmer 290B uses a grating with a dispersion of 16 A/mm, the Jarrell-Ash Dial-atom uses a grating with a dispersion of 33 A/mm, the Hilger-Watts Atomspek uses a prism with a dispersion of 17 A/mm at 2000 A, and Aztec Instruments model AAA-3 uses a grating with a reciprocal linear dispersion of 16 A/mm. 

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