Some practical experiences in the use of a solventless injection system for packed column supercritical fluid chromatography
✍ Scribed by Oudsema, John W. ;Poole, Colin F.
- Publisher
- John Wiley and Sons
- Year
- 1992
- Tongue
- English
- Weight
- 632 KB
- Volume
- 15
- Category
- Article
- ISSN
- 0935-6304
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✦ Synopsis
Abstract
The operating characteristics of a solventless injector for packed column supercritical fluid chromatography are described. Successful operation depends on the difference between the volatilities of the analytes and the solvent or matrix being sufficient for their separation by gas purging in a thermostatted precolumn, and also on the existence of an effective re‐focusing mechanism at the head of the analytical column for the sample dissolved in liquid or supercritical fluid carbon dioxide. The latter is easily achieved in density programmed operation by stationary phase trapping at low fluid densities or phase ratio trapping by changing the temperature at low to moderate fluid densities. The solventless injector can easily accommodate sample volumes from 1–100 μl and is easily adapted for in‐line derivatization using reagents which can, after reaction, be eliminated by gas purging. For general purposes the solventless injector can be used to overcome most of the problems encountered when rotary valve loop injectors are used with small bore packed columns, and will probably replace this type of injector as the injector of choice for supercritical fluid chromatography with mobile phases of low polarity.