Acceleration of free release static coating of capillary columns by the presence of polar solvents in the coating solution - a theoretical study

✍ Scribed by Xu, B. ;Vermeulen, N. P. E.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 744 KB
• Volume: 11
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240111006

✦ Synopsis

The cause of an observed acceleration in the free release static coating process of a capillary when more polar solvents are added to alkanes as stationary phase solvents has been studied. By using a computer program, 9 of the relevant physical parameters were calculated in relation to the composition of the solvent mixtures. Curves of these parameters vs composition of the mixtures were drawn. From the results it can be deduced that the change of these parameters with the increase of polar solvents in the solution, is probably insufficient to explain the drastic increase of the free release static coating speed. A physical model is proposed to calculate the depth ot the meniscus around which sufficient heat can be transferred into the evaporating surface per unit time, to evaporate the solvent at a rate that the coating speed indicates. It is demonstrated that when pentane-acetone mixtures are used to coat a capillary, the depth of the meniscus indeed is greater than when pure pentane is used. The proposed model may lead to a better understanding of phenomena involved in the static coating process.