PACKED-COLUMN SFC OF GAS OILS - PART II - EXPERIMENTAL-DESIGN OPTIMIZATION OF THE GROUP-TYPE ANALYSIS USING CO2-SF6 AS THE MOBILE-PHASE

An optimization procedure is presented for group-type analysis of dies el fuel by supercritical fluid chromatography using packed silica colu mn and a mixed mobile phase, A set of five responses, four values of r esolution of a performance mixture and analysis time, was modeled usin g a Doehlert matrix for experimental design, Optimized experimental co nditions for the five responses were obtained from a response surfaces optimization, taking into account various constraints on SF6 content in mobile phase and analysis time, The predicted and experimental reso lutions were in good agreement for the different optimized conditions and one of them was selected to for application to a given diesel fuel for comparison with the results obtained by SFC using pure CO2 and bg HPLC, The conditions found in this study provide an alternative metho d for the determination of mono-, di-, and polyaromatic compounds in m iddle distillates.