Column preparation drawing capillary columns

Halasz and Heine [115] used this method for the preparation of aluminum oxide columns. To retain an open passage inside the column, a steel wire with a diameter of 1 mm was inserted into the initial tube. In the course of drawing the softened glass carried the aluminum oxide particles away. The obtained 2-m column represented an intermediate variant of packed and open capillary columns with a fairly high efficiency (3500 theoretical plates per meter) with respect to ethylene. 

The method of preparation of sandwiched adsorption ca-pillary columns for gas chromatography is similar to that used for adsorbent layer formation during glass capillary drawing. Liberti, Nota, Goretti [8] use the term sandwiched capillary columns to describe columns made of any material, in which the separating medium is a thread inserted inside the capillary. Of course, any material which is available as thread can be used for preparation of sandwiched capillary columns. 

FIGURE 9 Column drawing apparatus for the preparation of fused silica capillaries. [From Lipsky, S. R., McMurray, W. J., Hernandez, M., Purcell, J. E., and Billeb, K. A. (1980). J. Chro-matogr. Sci. 18,1.]... 

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