Isocratic networks in supercritical fluid chromatography

✍ Scribed by Leyendecker, D. ;Leyendecker, D. ;Schmitz, F. P. ;Klesper, E.

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 382 KB
• Volume: 9
• Category: Article
• ISSN: 0935-6304
• DOI: 10.1002/jhrc.1240091005

✦ Synopsis

For chromatography with supercritical fluids (SFC), the dependence of the capacity ratios k and of the mean resolution R , on temperature and pressure is presented as a three-dimensional diagram. A sufficient number of test chromatograms were run for the diagram to lead to an isocratic network in form of a curved surface. The isocratic network possesses a characteristic shape and containsall information about the temperature and pressure dependence of k and R , for a given volume flow rate and chromatographic system. The specific system studied comprised pentane as the mobile phase, unmodified silica as the stationary phase, and a set of four polycyclic hydrocarbons as the test mixture. The isocratic net of this system allows interpolation of k and R , for any temperature and pressure. Together with similar experimental data from other systems, this allows qualitative forecasts about the isocratic nets of other systems.

phases or different substrates reveals a similar general dependence of these chromatographic data on pressure [l-121 and temperature [3,4,7-161. The dependences are usually nonlinear.

In the present work, many such test chromatograms were recorded with pentane as the eluent, unmodified silica as the stationary phase, and a substrate mixture of napthalene, anthracene, pyrene, and chrysene, using a constant volume flow rate for the mobile phase. Evaluating both k and R ,

, and plotting either one against temperature, T, and