In-situ fractionation—A simple technique for analysis complex mixtures using a routine-gas chromatograph

Summary

A simple in-situ fractionation technique, offering several advantages over conventional “heart-cutting” techniques, is described in which discrete, controlled fractions of effluent from one chromatographic column are transferred sequentially to a second column having diffierent selectively characteristics. Prior to transfer, solutes are stored in-situ on the first column, so that each fraction transferred can be analysed separatley on the second column. In-situ storage and fractionation is achieved using a simple flow-switching arrangement that can be installed in any routine chromatograph without extensive instrument modification. The gas chromatographic determination of aromatics in fuels having final boiling points up to 400° C is used to illustrate the technique. Its potential usefulness in gas chromatography and its possible uses in liquid chromatography are discussed.