Peak Compression Effects in Packed-Column Supercritical Fluid Chromatography

Peak compression in semi-preparative supercritical fluid chromatography

“…ric methods by Carlsson et al who found that it was strongly influenced by temperature, pressure, and modifier concentration [19]. Strode et al later found that peak compression generators, other than water, could be used for obtaining the effect [20]. The potential use of the peak compression phenomenon in the analytical scale, would be to increase peak detectability for a single species in a mixture.…”

“…Peak compression of clevidipine in packed supercritical fluid chromatography has been previously investigated, optimised and reported using typical analytical conditions [6,19,20]. It was shown that, after a chemometric optimisation of chromatographic parameters, when a 5 pL injection of clevidipine (0.2 mg mL -~) prepared in 70 % water, which corresponds to approximately 0.001 mg of sample injected, efficiencies of 135,000 were possible on a 200 • 4.6 mm ID packed column [19].…”

“…The principle of SFC peak compression has also been observed when samples containing water were injected to a silica column [6,19,20]. In these studies no practical pressure or density programming techniques were applied but compression was observed nevertheless, when direct injection of emulsion samples, which contained approximately 80 % water, were applied to the analytical column [6].…”

“…Preparative SFC system parameters were investigated with a view to obtaining conditions that may result in fractions of higher purity [18]. Potentially, another approach for obtaining fractions of higher purity would be, if possible, to apply a peak compression effect as described earlier for analytical scale SFC [6,19,20]. This effect in semipreparative or preparative scale SFC may present additional advantages over those observed in the analytical scale, although to our knowledge this has not been previously reported.…”

Packed column supercritical fluid chromatography of a peroxysome proliferator-activating receptor agonist drug

“…Development of a method for enantiomeric purity of bulk substance was fairly straightforward. Assay of the aqueous formulation, without any pre-treatment of the sample, was based on knowledge about what conditions to select in SFC in order to prevent irregularities in the chromatographic system due to water [16][17][18]. This information was not applicable, however, when the sensitivity had to be increased at least a 10-fold for the simultaneous estimation of the minor enantiomer ("impurity") in the aqueous formulation.…”