Page 356 - Academic Press Encyclopedia of Physical Science and Technology 3rd Analytical Chemistry

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Encyclopedia of Physical Science and Technology EN0011A-541 July 25, 2001 17:27

Organic Chemistry,

Compound Detection

Raphael lkan
Bernard Crammer
Hebrew University of Jerusalem

I. Introduction IX. Field-Flow Fractionation (FFF)
II. Chromatographic Methods X. Ion Chromatography (IC)
III. Flash Chromatography XI. Capillary Electrochromatography (CEC)
IV. Droplet Countercurrent Chromatography XII. Spectroscopic Methods
V. High-Pressure Liquid Chromatography XIII. X-Ray Crystallography
VI. Gas Chromatography XIV. Chemical Analysis
VII. Supercritical Fluid Chromatography XV. Future Prospects
VIII. Thin-Layer Chromatography

GLOSSARY or interact with specific functional groups causing the
required separation.
Capillary electrochromatography (CEC) Technique Coupled chromatographic and spectroscopic tech-
wherein a packed bed capillary with smaller pack- niques Method involving a chromatographic system
ing particles than in HPLC systems is used. It uses such as GLC or HPLC connected to a mass spectrome-
electroosomotic flow (EOF) rather than high pres- ter or FTIR spectrometer in order to analyze individual
sure to force the mobile phase through the cap- components from a mixture of organic compounds in
illary. minute (submilligram) quantities.
Chromatography Method of separating two or more Deuterium exchange Replacement of hydrogen atoms
substances by distribution between two phases, one by deuterium atoms usually by means of active com-
fixed (the stationary phase) and the other moving (the pounds containing deuterium such as D 2 O and NaBD 4 .
mobile phase). The percentage of deuterium exchange may be deter-
Chromatography of isomers Chromatographic separa- mined by spectroscopic analysis.
tionofgeometric(cis-trans)andoptical(R and S)enan- Diffuse reflectance IR spectroscopy (DRIFTS) Pene-
tiomers on adsorbents that have been impregnated with tration of infrared radiation onto a solid sample before
compounds having the ability to complex preferentially the radiation is scattered.

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