Inventors:
Lenore R. Frank - Landenberg PA
Christoper M. Wurm - Landenberg PA
Paul C. Dryden - West Chester PA
Steven J. Engel - Kennett Square PA
Mark A. Nickerson - Landenburg PA
Ernest Zerenner - Wilmington DE
Assignee:
Hewlett-Packard Company - Palo Alto CA
International Classification:
B01D 1508
Abstract:
Methods and apparatus for extracting sample components from complex matrices using supercritical fluid as the principal extracting solvent are disclosed. The invention takes advantage of the fact that the solvent power of a supercritical fluid is stepwise settable by the parameters of density, modifier concentration, and temperature. Accordingly, methods and apparatus for extracting a component from a sample using fluid flow system having a variable and controllable flow restriction are disclosed. The methods of the present invention comprise the steps of inserting the sample into the sample container section, inputting temperature, pressure, flow rate and extraction time set points. Flow rate is controlled and system pressure regulated by the variable flow restriction. The invention contemplates opening and closing an orifice in order to control the variable flow restriction, or closing the orifice until set point pressure is achieved and controlling the restriction of the orifice to maintain the set point pressure.