Who says Raman spectroscopy is only good for research? W i t h the advent of the laser, Raman spectroscopy became a superb research technique. But it hasn't stopped there. N o w , the Cary 83 Spectrophotometer makes Raman practical for the analytical lab as well. It's simple to operate, economical to o w n . For instance, the Cary 83 complete with argon ion laser costs only $14,900. Furthermore, it's the perfect complement to your infrared studies. A COMPLEMENT PLUS
Cary 83
Its vibrational sensitivity is excellent. Many group frequencies, weak or absent in infrared, yield strong Raman bands. Cis-trans isomers and carbon-carbon skeletal modes are more readily characterized. In general, symmetric vibrations are weak in infrared, strong in Raman. It makes sample preparation simple. You don't have to mix the samples with anything, whether liquid, powder, gas, or polymer. You can even scan a single crystal, regardless of size or shape. That's practically impossible w i t h infrared.
But don't just think small. Take the cover off the sample compartment, and if you can fit the specimen in the lab, you can usually get a spectrum.
But the instrument doesn't stop there either. The 83 can handle all types of aqueous samples. Since water is a very weak Raman scatterer, it makes a great solvent, especially for biological studies. Not true with infrared. Then there's its wide wavenumber range of from near 0 to 4000Acm _ 1 . That's almost the entire range of molecular vibrational frequencies. You w o u l d need at least two infrared instruments to span that. This spectrum of powdered iodic acid was run in less than 3 minutes on the Cary 83. No sample preparation was necessary. 500
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A n d it makes polarization measurements easy. The laser source is highly polarized, which lets you determine polarization ratios accurately and simply. N o w you can tell which bonds arise from totally symmetric molecular vibrations.
THINK RAMAN If you haven't been thinking Raman, we have two excellent article reprints to get you started. They come with a brochure on the Cary 83, the Raman complement to infrared. Write for data file A 201 -22.
cary instruments a varian subsidiary 2724 s. peck road/monrovia, California 91016
CIRCLE 35 ON READER SERVICE CARD A N A L Y T I C A L CHEMISTRY, VOL. 4 4 , NO. 7, J U N E 1 9 7 2
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