Decoupled flow and pressure setpoints in an extraction instrument using compressible fluids
US5094741A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 18, 1990 |
| Grant date | Mar 10, 1992 |
| Priority date | — |
| Expiry date | May 18, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2030/324
- WIPO fieldMeasurement
- WIPO sectorInstruments
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. The present invention also discloses apparatus for the extraction of components from a sample which include means for regulating the pressure and flow rate of a superc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.