Raman Spectroscopy - Instrumental Analytical Chemistry - Lecture Slides, Slides of Analytical Chemistry

Download Raman Spectroscopy - Instrumental Analytical Chemistry - Lecture Slides and more Slides Analytical Chemistry in PDF only on Docsity! Chapter 18 Raman Spectroscopy Docsity.com Rayleigh scattering Vo = 20492 em Ag = 488.0 nm intensity 400 200 6 200 -400 AY, em! Figure 18-1 Raman specitum for CCl excited by laser tadiation of kg = 488 nm and ¥y = 20,492 cm-!. The number above the peaks is the Raman shift, AF = (¥, — ji) cmo!, (Reprinted with permission from D. P Strorament and K, Noakamato, Amet, Lab., L982, 43, (10), 72, Copyright 1981 by Intera- tional Scientific Comnnmications, lnc.) Docsity.com a Polarized radiation from laser ‘> 184 Depolarization resulting from Raman scattering. Depolarization ratio = p = 4 Perpendicular polarizer Partially fy depolarized <al ill) (/; (lh, | sacred “WU Parallel polarizer fy Docsity.com TABLE 18-1 Some Common Laser Sources for Raman Spectroscopy 488.0 or 514.5 530.9 or 647.1 632.3 782 or 830 1064 ® Docsity.com  B 500 1000 1500 =. 2000 2500 3000 3500 Raman shift (em) Figure 18-8 Spectra of anthracene. A: Conventional in- strument, 5145 A excitation, B: FT instrament, 1,064 um excitation. (From 8. Chase, Anal, Chem.,, i987, 59, 888A. With pecmission. Copyright 1987 Amerlaan Chemical Society.) Docsity.com j "Raman emission intensity, arbitrary units | I I | | I i | 1700 8 AY, cm! Figure 18-8 Spectrum of molten polyethylene obtained using fiber-optic probe inserted into the polymer melt. ron. k. L. MeCreery, M. Fleischmann, and P. Hendra, Anal. Chem., 2983, 55, 146. With perntissiot.) ® Docsity.com LN, cooled Fined minor Sample Beam ae 200-mm Parabolic eallection mirror NdgYAG laver vith line filter Higure 18-9 Optical diagram of an FI-Raman spectrometer (LN2 = liquid nitrogen). (from. B. Chase, Anal. Chem, 1987, 59, 8844. With permission.) 3 Docsity.com  Figure 18-10 Multichannel dispersive Raman spectrometer with a charge-coupled de vice (CCD). BP is an interference band-pass filter; BR is a Rayleigh band-rejection filter. (Adapied from C.D. Newman, GC. Bret, and RL. MeCreery, Appl. Spectros., 1992, 46, 263. With permils- slow.) ® Docsity.com