SOLID-PHASE TRAPPING MECHANISMS INVOLVED IN THE SUPERCRITICAL-FLUID EXTRACTION OF DIGITALIS GLYCOSIDES WITH MODIFIED CARBON-DIOXIDE

Understanding and optimizing the variables involved in the collection of the extracted analytes are as important as understanding and optimizing the extraction variables themselves. It has been shown here that the method by which the modifier is introduced can have an effect on one's ability to trap the components quantitatively. The ability of the solid phase to quantitatively trap extracted components at high modifier percentages, as well as the type of mechanism that gives rise to sample loss from a tandem trapping system, has been shown to be dependent on now rate and trapping temperature. It is further shown that the optimum trap temperature and now rate combination for extractions where high modifier levels are employed exists at high trap temperature, to boil away any modifier, and low now rates, to maximize contact time with the trap.