A Novel Method for Collecting Samples for Infrared Identification
The selection of the best technique and apparatus for collecting individual components from gas chromatographic separations depends on the type of compound, its concentration in the sample, and the separation available. A new technique is described for concentrating an impurity in the difficult case of a sample having an impurity of less than 10%, which impurity elutes just before the major peak (> 80%) with almost baseline resolution at this concentration, and the retention time of which is several minutes. Concentration of this minor component is done on the collector which, after several trappings, also becomes the sample introduction instrument. Following the concentration step, the minor component may be adequately resolved on the analytical column and collected from it by such means as deposition on a salt plate or condensation in a microcell. This concentration technique allows the analytical column used to accomplish the initial separation also, to be used instead of a preparative column in the separation of minor components for subsequent identification by infrared examination. Much time is saved in comparison with that required for the conventional, more cumbersome preparative column technique, and the same result is accomplished.
KeywordsMajor Peak Analytical Column Isothermal Temperature Preparative Column Baseline Resolution
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