Effect of reference conditions on flow rate, modifier fraction and retention in supercritical fluid chromatography

Ruben De Pauw, K. Choikhet, Gert Desmet, Ken Broeckhoven

Onderzoeksoutput: Articlepeer review

11 Citaten (Scopus)

Samenvatting

When using compressible mobile phases such as fluidic CO2, the density, the volumetric flow rates and volumetric fractions are pressure dependent. The pressure and temperature definition of these volumetric parameters (referred to as the reference conditions) may alter between systems, manufacturers and operating conditions. A supercritical fluid chromatography system was modified to operate in two modes with different definition of the eluent delivery parameters, referred to as fixed and variable mode. For the variable mode, the volumetric parameters are defined with reference to the pump operating pressure and actual pump head temperature. These conditions may vary when, e.g. changing the column length, permeability, flow rate, etc. and are thus variable reference conditions. For the fixed mode, the reference conditions were set at 150 bar and 30 °C, resulting in a mass flow rate and mass fraction of modifier definition which is independent of the operation conditions. For the variable mode, the mass flow rate of carbon dioxide increases with system pump operating pressure, decreasing the fraction of modifier. Comparing the void times and retention factor shows that the deviation between the two modes is almost independent of modifier percentage, but depends on the operating pressure. Recalculating the set volumetric fraction of modifier to the mass fraction results in the same retention behaviour for both modes. This shows that retention in SFC can be best modelled using the mass fraction of modifier. The fixed mode also simplifies method scaling as it only requires matching average column pressure.
Originele taal-2English
Pagina's (van-tot)129-135
Aantal pagina's7
TijdschriftJournal of Chromatography A
Volume1459
DOI's
StatusPublished - 12 aug 2016

Vingerafdruk

Duik in de onderzoeksthema's van 'Effect of reference conditions on flow rate, modifier fraction and retention in supercritical fluid chromatography'. Samen vormen ze een unieke vingerafdruk.

Citeer dit