Principles and Practice of Chromatography - Chromatography Applications > Gas Chromatography Applications > High Temperature GC Stationary Phases > Page 73

Courtesy of Mr. Andrew Lynn of the Dexsil Corporation

Figure 36 The Separation of a High Molecular Weight Hydrocarbon Wax on a High Temperature Stationary Phase

As would be expected the more polar the stationary phase the lower the temperature stability. An example of the use of Dexsil 400 to separate some very high boiling waxes is shown in figure 36.

The column was programmed from 50˚C to 380˚C at 4˚C /min. and held at 380˚C for 6.5 min. The carrier gas flow rate was 30 ml/min. The wax components are well resolved and the baseline appears very stable even a 380˚C. The stable base line, with no drift, indicates there is little or no decomposition of the solutes or the stationary phase, even at 380˚C. Stationary phases based on the carborane structure, can extend the temperature range of gas chromatography very significantly, However, having thermally stable stationary phases solves only half the problem, the solutes themselves must be equally stable.