SUPERCRITICAL-FLUID EXTRACTION OF METAL-CONTAINING SELECTIVE SORBENTS

Nickel(II), copper(II), zinc(II) and lanthanum(III) complexes with bis -beta-diketonate ligands form polymeric materials that function as sel ective sorbents for use as gas chromatographic precolumns. Supercritic al fluid extraction was evaluated as a method of desorbing compounds r etained by these sorbents. Alcohols, ketones, esters and sulfur-contai ning compounds were effectively extracted using carbon dioxide at 80 a tm (1 atm = 101 325 Pa) and 50-degrees-C. The blanks observed with sup ercritical fluid extraction were often better than those obtained with thermal desorption. The applicability of supercritical fluid extracti on is demonstrated on the constituents of cigarette smoke retained on a copper-containing sorbent. Two other sorbents employing metal comple xes of either a beta-diketone derivative of polystyrene or a beta-keto amide derivative of silica gel were evaluated. The blanks with these m aterials were not found to be suitable using either thermal desorption or supercritical fluid extraction.