About 9.0 g of PKC sample with particle size 6425 lm were put
into a 10 ml cylindrical extraction vessel which was placed in the
oven; the oven temperature was set as the desired extraction temperature.
The experiment was carried out by operating the system
with carbon dioxide with a purity 99 g kg1, which was condensed
in a refrigerated bath to 0 C. The liquid CO2 was compressed to the
predefined pressure and then pumped into the heated extraction
cell that contained the sample. Subsequently, the CO2 was heated
to the required temperature to achieve the supercritical state