Absolute gas chromatography

Abstract

A gas chromatographic technique is reported that is absolute in the sense that the molar composition of a sample can be determined without the need for calibration. It functions by measuring the volumetric flow rate of the stream leaving a chromatographic column: the flow rate changes temporarily when a peak emerges. Because volumetric flow rate is measured, the resulting chromatogram is much more closely related to quantities of material than is a conventional chromatogram. The simple theoretical development and equally simple design refinement that make the method absolute are described here together with a severe experimental test of the method.

Flux response technology applied in zero length column diffusivity measurements

“…Adapting the ZLC technique in FRT system provided the additional capability of measuring fast diffusion processes by taking advantage of the very sensitive DPT. The FRT system responds to any substance whose extent of sorption differs from that of the carrier, thereby making it possible to measure flow rate changes instantaneously as the capillary detection system behaves as though it has no volume (Buffham et al 1993). The arrangement of the DPT and matched capillaries provide the system with a resolution of one part in ten thousand, however, the response time of the system can be reduced further still at the expense of the sensitivity and vice-versa (Buffham et al 1986a(Buffham et al , 1986b.…”