High-speed gas chromatography with direct resistively-heated column (ultra fast module-GC)-separation measure (S) and other chromatographic parameters under different analysis conditions for samples of different complexities and volatilities

The influence of GC speed on the separation capability of a chromatographic system is reported measuring a series of parameters including separation measure (S), peak capacity (n), peak width ( w ), analysis time, tb (determined on the last eluting compound) and separation measure/analysis time ratio (S/tb) determined by analyzing a bergamot essential oil sample and a standard mixture of pesticides. Conventional GC, fast GC (with 10 m (FGC10) and 5 m (FGC5) narrow-bore columns), and direct resistively-heated ultra fast module-GC (UFM-GC) were the GC speed approaches used. The influence of different heating rates with a constant flow for FGC5, FGC10, and UFM-GC and with variable flows for UFM-GC on S, n, w , S/tb, and tb was also studied. sults of this study show that:(a) tion capability of the chromatographic system (i.e. S and n) and analysis time depend on the GC approaches. Within each GC approach, S and n and analysis time depend on the heating rates, although to a different extent, and S and n decrease much less than the gain in analysis time, in particular when fast heating rates are applied; -GC, the loss of separation capability with heating rate can also be partially compensated by the choice of an appropriate flow rate that, within each heating rate, may contribute to increase S while reducing tb; a specific GC approach, the chromatographic system (column and stationary phase) and conditions (heating and flow rates) must be such to achieve a suitable S-value when two analytes must be separated with a given resolution in a minimum analysis time.