ABSTRACT
Two common fat retainers used in supercritical fluid extraction--basic alumina and the silica based adsorbent Florisil--were investigated using lard fat as model material. With a fat retainer in the extraction cell it was possible to obtain fat-free time windows. Activation by heating did not influence the length of the time windows, while deactivation of the retainers with 10% water (w/w) drastically decreased the fat retaining capabilities. The influence of modifier addition was also investigated. Finally, a method was developed, where basic alumina was utilized to selectively extract polychlorinated biphenyls (PCBs) from a model fat sample, containing PCBs, triglycerides and phospholipids. The PCBs could be quantitatively extracted in a totally fat-free time window.
Subject(s)
Chromatography/methods , Fats/chemistry , Polychlorinated Biphenyls/isolation & purificationABSTRACT
The purpose of this study was to find materials that can be used as a solid phase trap in a commercial supercritical fluid extraction instrument. PX-21 active carbon mixed with ODS proved to yield the best results. After SFE of the target compounds, the planar fraction containing the environmental pollutants PCDDs, PCDFs, and planar PCBs was successfully separated on a PX-21 solid phase trap from the nonplanar fraction containing the other PCBs and pesticides. Direct injection of the concentrated fractions on GC/MS was possible without further cleanup. SFE followed by on-line carbon column chromatography was tested using standard solutions (applied on filter paper) as well as biological samples (human adipose tissue).
