SMALL SAMPLE HANDLING IN LASER RAMAN SPECTROMETRY

Several reports have appeared recently (1-3) pertaining to the generation of Raman spectra by laser excitation of small samples. Bailey, Kint, and Scherer (3) adopted the axial excitation/viewing geometry (Figure 1, left) of Porto (4), and reported spectra from as little as 0.04 µl of CC14 in specially fabricated capillary cells. However, this system gives poor depolarization ratios for the 218, 314, and 459 A cm-1 bands. Dr. J. R. Scherer recently advised us that the system has been improved and it now yields good results on 0.04-µ1 sample quantities. Pez (5) obtained Raman spectra of liquids in 1.0-mm bore melting point capillaries by transverse irradiation/viewing (Figure 1, right). Unlike the tube with a single focused hemispherical lens of the type. © 1969, American Chemical Society. All rights reserved.