Rapid Sample Preparation for Analytical Analysis Using Dispersive Energized Extraction

Abstract

An extraction method for preparing samples for analytical analysis is disclosed. The method includes the steps of placing a sample matrix containing one or more analytes in a heat conductive sample cup, positioning the heat conductive sample cup in a pressure-resistant reaction chamber, dispensing solvent into the heat conductive sample cup, dispersing the solvent and the sample matrix in the sample cup in the reaction chamber, heating the sample matrix and the extraction solvent in the heat conductive sample cup in the reaction chamber to a temperature at which the dispensed solvent generates an above-atmospheric pressure, and releasing the extraction solvent extract from the sample cup at atmospheric pressure.

1 . An extraction method comprising the steps of:
 placing an extraction sample in a heat conductive sample cup surrounded by a reaction chamber with the heat conductive sample cup having one opened filtered end;   adding liquid extraction solvent to both the inside of the sample cup and to the reaction chamber outside of the sample cup; and   heating the liquid extraction solvent in the reaction chamber outside of the sample cup to in turn   heat the sample cup, heat the liquid extraction solvent inside the sample cup, and heat the extraction sample inside the sample cup.   
     
     
         2 . An extraction method according to  claim 1  wherein the step of heating the liquid extraction solvent outside of the sample cup comprises heating the reaction chamber. 
     
     
         3 . An extraction method according to  claim 1  wherein:
 the sample cup has a mouth opposite from its open filtered end; and 
 the extraction method further comprises: 
 sealing the sample cup between a sealing cover at the vessel mouth and an outlet valve in the reaction chamber so that the heating step increases the vapor pressure of the extraction solvent above the solvent's vapor pressure at ambient temperature and pressure. 
 
     
     
         4 . An extraction method according to  claim 3  further comprising pre-pressurizing the reaction chamber to about 25 psi between the steps of placing the extraction sample in the sample cup and of heating the liquid extraction solvent in the reaction chamber. 
     
     
         5 . An extraction method according to  claim 3  wherein the step of adding liquid extraction solvent into the sample cup is carried out from positions selected from the group consisting of the top of the sample cup, the bottom of the sample cup, and both the top and bottom of the sample cup. 
     
     
         6 . An extraction method according to  claim 3  and further comprising releasing the outlet valve on the reaction chamber so that the vapor pressure in the reaction chamber drives the extraction solvent out of the sample cup through the open filtered end and through the outlet valve. 
     
     
         7 . An extraction method according to  claim 6  further comprising driving the solvent into a cooling coil in liquid communication with the outlet valve in the reaction chamber, and in which the cooling coil has a length sufficient to reduce the temperature of common extraction solvents for a time sufficient to reduce the temperature of the extraction solvent to below the solvent's boiling point at ambient pressure in the cooling coil. 
     
     
         8 . An extraction method according to  claim 7  wherein the step of driving the liquid extraction solvent comprises:
 driving the liquid extraction solvent into the cooling coil until the drained extraction solvent extract approaches or reaches ambient temperature; and 
 collecting the cooled extraction solvent extract for analysis. 
 
     
     
         9 . An extraction method according to  claim 1  and further comprising agitating, and pressurizing the extraction solvent and the sample matrix in the sample cup. 
     
     
         10 . An extraction method according to  claim 9  wherein the opened filtered end of the sample cup supports a filter or filter media and allows solvent extract to drain from the sample cup. 
     
     
         11 . An extraction method according to  claim 9  wherein the agitating step comprises bubbling gas that is inert to the sample matrix through the bottom of the sample cup. 
     
     
         12 . A method according to  claim 9  wherein the agitating step is carried out prior to the heating and pressurization steps. 
     
     
         13 . An extraction method according to  claim 9  further comprising applying ultrasonic agitation during the pressurized heating step. 
     
     
         14 . A method according to  claim 1  further comprising conductively heating the reaction chamber to a temperature of between about 90° C. and 180° C. and generating resulting pressures of between about 50 and 250 psi. 
     
     
         15 . An extraction method according to  claim 1  wherein the extraction solvent is selected from the group consisting of water, weak acids, weak bases, ethyl acetate, methyl tertiary-butyl ether (“MTBE”), methylene chloride, hexane, acetone, hexane 2-propanol, cyclohexane, acetonitrile, methanol and mixtures thereof. 
     
     
         16 . A heated pressurized agitated mixture of an extraction solvent and a sample matrix containing an analyte in a heat conductive sample cup that is inside of a reaction chamber that also contains heated extraction solvent outside of said sample cup. 
     
     
         17 . An extraction method for preparing analytes for molecular analysis comprising dispersing an extraction solvent and a sample matrix containing an analyte after the extraction solvent and the sample matrix analyte have been placed into a heat conductive sample cup and, heated, and pressurized.