Mdl. Decastro et Mt. Tena, STRATEGIES FOR SUPERCRITICAL-FLUID EXTRACTION OF POLAR AND IONIC COMPOUNDS, TrAC. Trends in analytical chemistry, 15(1), 1996, pp. 32-37
The methods used to facilitate the supercritical fluid extraction (SFE
) of polar and ionic compounds are based on two general principles, ei
ther increasing the polarity of the supercritical fluid (SF) (usually
CO2) used as extractant or reducing the polarity of the analytes to be
leached from the solid matrices. Changes in the pressure and temperat
ure of the SF, the use of SFs more polar than CO2 or of modified CO2,
ion pair formation, esterification, the use of and organometallics, or
complex formation are the most common ways of increasing the extracti
on efficiency for polar and ionic analytes.