Sample introduction in high speed capillary gas chromatography; input band width and detection limits

Summary The speed of analysis in capillary gas chromatography can be substantially increased by reduction of the column inner diameter. However, special demands are then posed upon instrumental design. In particular, the sampling system is highly critical because it has to be capable of delivering extremely small injection band widths which must be compatible with the column inside diameter. This study focuses on the evaluation of two potentially suitable sample introduction systems with respect to input band width and detection limits and their compatibilitywith small bore (5 100 pm)columnsincapillarygas chromatography. One of them allows liquid on-column injection, based on liquid splitting, of only a few nl onto small bore (5 100 4m) fused silica columns. Forgases, input band widthsas low as 1 ms are obtained with this system. The other one is part of a miniaturized gas chromatograph with extremely low dead volume interfaces and detector volumes. It allows input band widths for gases of a few ms. Without any preconcentration ppm concentrations are measured in gaseous samples with a 80 4m thick film capillary column. It will be shown that a further reduction of the minimum detectable amount and analysis time is possible with this equipment.