Download Infrared Resources - Instrumental Analytical Chemistry - Lecture Slides and more Slides Analytical Chemistry in PDF only on Docsity! TABLE 16-1 Infrared Spectral Regions
Region Wavelength (\) Range, um Wavenumiber (7) Range, cm-1 Frequency (»} Range, Hz
Near 0.78 to 2.5 12,806 to 4000 3.8 * 104 to 12 1014
Middle 2.5 ta 50 4000 to 200 12x 10! to 6.0 x 1012
Fat 50 to 1000 200 to 10 6.0 X 10 to 3.0 x 101
Mostused 2.5 to 15 . 4000 to 670 12 X 10'* to 20x 108
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5
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Li
L600 i406 1200 0
1800
2400 2000
2800
3200
3600
10 }-
9
4000
(q%) somenpOsael
Frequency, em?
Higare 16-1 Infrared absorption spectrum of a thin polystyrene film recorded with a
modern infrared spectrophotometer Note that the abscissa scale changes at 2000 cm!.
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1000
100 -
10
Energy, arbitrary units
Figure 16-4 Spectral distribution of energy from a
Cae glower operated at approximately 2200 K.
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Infrared Resources Docsity.com Spectrophotometer
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Figure 16-5 Thermocouple and preamplifier. (Adapted fiom G. W. Ewing, J. Chem.
Ce 1971, 48, ASZ1. With permission.)
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AIM-8800 Infrared Microscope Docsity.com Perkin Elmer - Spectrum Spotlight 200 FTIR Microscope System Docsity.com Varian FTIR Microscopy Docsity.com Sampling Accessories ATR Docsity.com Sampling Accessories HATR Docsity.com Sampling Accessories Specular Reflectance Docsity.com 4000 2500 Wavenumber, em!
soo | 3000 | 2000 1500 1300 1100 1000 = 900 800 700-650
100 T T T T T T T i T I T T T T T T T a T T T T T T I T
90 = Double-beam mode
j 80 —
70
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5 50 mode
= 40
H 30
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6 20
10
oF l I i I I L | 1 1 I | 1 I i ! 1 i 1 l l }
2 3 4 5 6 7 a 9 10 1 12 13 14 is 1
Wavelength, pm
Hgure 16-9 Single- and double-beam spectra of atmospheric water vapor and CQz. In the
lower, single-beam trace, the absorption of atmospheric gases is apparent. The top, double-beam
trace shows that the reference beam compensates nearly perfectly for this absorption and allows
astable 100% T baseline to be obtained. (From J. D. ingle jr. and & R. Crouch, Spectrochemical Analysis,
A. 200. Pnolewaad Ci. NT: Prentice-Hall. 1988. Wid wermiscar
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Figure 16-20 Schematic of a double-beam spectrophotometer. Heavy dark
line indicates mechanical linkage; light line indicates electrical linkage; dashed
line indicates radiation path.
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Wavenumber, em
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Figure 16-11 Infrared spectrum of n-hexanal illustrating overshooting at low %T-
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