Dense-gas chromatography

In terms of chromatography, the first individual credited with the use of supercritical fluids as the mobile phase is Ernst Klesper when in 1962 he reported on the separation of metal porphyrins using dense-gas chromatography (GC) or SFC [3]. But it was not until the 1980s that the analytical community took hold of the abilities and advantages of the technique with the advent of several commercial instrumentation ventures. 

Dense-Gas Chromatography of Nonvolatile Substances of High Molecular Weight, L. McLaren, M. N. Myers, and J. C. Giddings, Science, 159, 197 (1968). Nonequilibrium Theory of Field-Flow Fractionation, J. C. Giddings, J. Chem. Phys., 49, 81 (1968). 

Randall, L. G. 1982. The present status of dense (supercritical) gas extraction and dense gas chromatography Impetus for DGC/MS development. Sep. Sci. Tech. 17 1. 

McLaren L, Myers M N, Giddings J C 1968 Dense-gas chromatography of nonvolatile substances of high molecular weight. Science 159 197-199... 

Depending upon the choice of temperature and pressure, the behaviour of a supercritical fluid can sometimes looks like a dense gas and sometimes like a liquid. For these reasons, use of supercritical fluids as mobile phases in chromatography presents certain advantages. 

A schematic diagram of a typical hollow fiber dense membrane reactor is shown in Figure 37.5a. The hollow fibers (Figure 37.5b) are manufactured by a phase inversion process (OD = l.1-1.5 mm ID = 0.75-1 mm) [63,64]. The oxidant gas (O2, H2O, CO2, N2O) mixture is fed to the core side, while a fuel (CH4, CO, or H2) mixture is fed to the shell side. A catalyst can be packed on the shell side. Both exit hnes are continuously monitored by onhne gas chromatography or mass spectrometry. 

Configuration of the dense ceramic hollow fibre membrane reactor. In the figure GC refers to gas chromatography. 

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