| 摘要 |
Hydrocarbon oils such as diesel fuels, turbine fuels and intermediate distillates may be subjected to quantitative analysis of their saturate, aromatic and polar components by supercritical fluid chromatography using carbon dioxide as the solvent. A sample of the oil is passed into a packed column of silica or the like whereby the respective fractions are separated and retained on the column. Supercritical carbon dioxide at selected pressure and temperature conditions is passed through the column to extract, separately, each of the fractions retained on the column. The extracted fraction and solvent are passed through a restrictor and expanded down to a pressure which will allow the solvent to evaporate and to permit retention or collection of the extracted fraction in a collector arrangement including a selector valve and plural collection containers. Supercritical carbon dioxide is supplied to the column through an injector valve by way of a pump which may be operated to provide the solvent fluid at a selected pressure in accordance with the fraction to be extracted.
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