Cryogenic solute manipulation in gas chromatography - the longitudinal modulation approach

Longitudinal modulation of chromatographic bands by using a cryogenic syste m gives a new way of handling and processing migrating solutes in capillary columns. Whilst trapping of volatile components in cooled devices is a wel l understood and widely used phenomenon, being able to remobilize the trapp ed component in the manner described in this article allows a number of new methods to be used during chromatograph analysis. The longitudinally modul ated cryogenic system (LMCS) can be placed at the start, end or mid-region of the column, and each of these produces specific benefits according to ho w the system is employed. Whilst its use in single dimensional analysis is reasonably straightforward, its potential in multidimensional gas chromatog raphy should show great promise. An application describing a robust and eas ily implemented comprehensive GC method offers the analyst entry into very powerful separation technology, which could very well represent the future approach to complex mixture analysis. (C) 1999 Elsevier Science B.V. All ri ghts reserved.