Potentialities of micropacked columns. Some applications in petroleum chemistry

Packed columsn of an internal diameter of 0.6–0.8 mm and lengths of up to 15 m were prepared. Theoretical plate numbers of the order of 50 000 at moderate inlet pressures were obtained. A homogeneous particle size was found to be essential. The columns are coiled and subsequently packed under pressure and vibration. A distinct advantage over the packed capillary columns according to Halasz and Heine is that all types of support, coated with any stationary phase, may be used (e.g., Porapak, Durapak, silanized glass beads). The packing may be prepared in large batches, ensuring reproducible columns. The small volume makes the use of expensive packings feasible. Sample size is such that direct injection presents no difficulties. A few applications to hydrocarbon mixtures are given