Applications of the chromatographic impulse response method in supercritical fluid chromatography

Infinite dilution partial molar volumes of platinum(II) 2,4-pentanedionate in supercritical carbon dioxide

The effects of temperature and density on retention of platinum(II) 2,4-pentanedionate in supercritical fluid chromatography were investigated at temperatures of 308.15-343.15K and pressure range from 8 to 40MPa by the chromatographic impulse response method with curve fitting. The retention factors were utilized to derive the infinite dilution partial molar volumes of platinum(II) 2,4-pentanedionate in supercritical carbon dioxide. The determined partial molar volumes were small and positive at high pressures but exhibited very large and negative values in the highly compressible near critical region of carbon dioxide.

Binary Diffusion Coefficients of Platinum(II) Acetylacetonate in Supercritical Carbon Dioxide

Binary diffusion coefficients (D₁₂) and retention factors (k) of platinum(II) acetylacetonate at infinitesimal concentration in supercritical (sc) carbon dioxide (CO₂) were measured by the chromatographic impulse response method with a poly(ethylene glycol) coated capillary column at temperatures from (308.15 to 343.15) K and pressures from (8.5 to 40.0) MPa, and D₁₂ in liquid ethanol at temperatures from (298.15 to 333.15) K and atmospheric pressure by the Taylor dispersion method. As has been seen for our previously reported data on other metal complexes measured in sc CO₂ and organic solvents, the D₁₂ data in sc CO₂ and liquid ethanol were represented by a function of temperature and solvent viscosity. The D₁₂ values for metal complexes were not related to the solute molecular weights. The k values in sc CO₂ were expressed by a function of temperature and CO₂ density.