VARIATION IN THE SUPERCRITICAL-FLUID EXTRACTION OF POLYCHLORINATED-BIPHENYLS AS A FUNCTION OF SORBENT TYPE, EXTRACTION CELL DIMENSIONS, AND FLUID-FLOW RATE

The type of solid-phase sorbent used is shown to influence the observed effect of extraction vessel dimensions on the supercritical carbon dioxide extraction of polychlorinated biphenyls (PCBs). The effect of using extraction vessels of different dimensions (i.d. to length ratio) ranged from negligible to substantial, depending on the sorbent type used. The effect of fluid flow rate (extraction time at constant volume) on the supercritical fluid extractions (SFE) of PCBs from common sorbents, again, varied from negligible to substantial, depending on the sorbent type that was used. The results highlight the difficulty in making generalizations about the relative effects of experimental variables when using the supercritical fluid extraction of analytes from solid-phase sorbents. Additionally, SFE of the PCBs from the clay material, kaolin, showed recovery differences possibly related to the planarity of the PCBs studied. © 1973, Oxford University Press. All rights reserved.