Vacuum-assisted sample extraction device and method

Abstract

A sample extraction device and a desorption device for use in gas chromatography (GC), gas chromatography-mass spectrometry (GCMS), liquid chromatography (LC), and/or liquid chromatography-mass spectrometry (LCMS) are disclosed. In some examples, the sample extraction device includes a lower chamber holding a sorbent. The sample extraction device can extract sample headspace gas from a sample vial by placing the sorbent inside the vial and creating a vacuum to increase recovery of low volatility compounds, for example. Once the sample has been collected, the sample extraction device can be inserted into a desorption device. The desorption device can control the flow of a carrier fluid (e.g., a liquid or a gas) through the sorbent containing the sample and into a pre-column and/or a primary column of a chemical analysis device for performing GC, GCMS, LC, LCMS, and/or some other chemical analysis process.

1 . A method comprising:
 providing a sorbent in a headspace of a system, the sorbent disposed within a tube, and the system containing a sample;   drawing a vacuum in the system with a vacuum source; and   after drawing the vacuum with the vacuum source and while the vacuum is maintained in the system, causing transfer of one or more volatile compounds of the sample to the sorbent for subsequent chemical analysis.   
     
     
         2 . The method of  claim 1 , further comprising after transferring the one or more volatile compounds of the sample to the sorbent, chemically analyzing the one or more volatile compounds that are in the sorbent. 
     
     
         3 . The method of  claim 2 , wherein the chemically analyzing includes transferring the one or more volatile compounds from the sorbent via thermal desorption. 
     
     
         4 . The method of  claim 2 , wherein the chemically analyzing includes transferring the one or more volatile compounds from the sorbent via solvent extraction. 
     
     
         5 . The method of  claim 1 , wherein the system is a closed system. 
     
     
         6 . The method of  claim 1 , wherein the system comprises a sample vial. 
     
     
         7 . The method of  claim 1 , further comprising:
 after transferring the one or more volatile compounds of the sample to the sorbent for subsequent chemical analysis, removing the one or more volatile compounds of the sample from the sorbent such that no volatile compounds remain in the sorbent and re-using the sorbent to collect one or more volatile compounds of a second sample different than the sample.   
     
     
         8 . The method of  claim 1 , further comprising:
 sealing the system.   
     
     
         9 . The method of  claim 1 , wherein the vacuum is maintained in the system and transfer of the one or more volatile compounds of the sample to the sorbent occurs during a period of time is in the range of one minute to twenty-four hours. 
     
     
         10 . The method of  claim 1 , wherein the vacuum is maintained in the system and at least partial transfer of the one or more volatile compounds of the sample to the sorbent occurs during a period of time is in the range of ten minutes to 16 hours. 
     
     
         11 . The method of  claim 1 , wherein the vacuum is maintained in the system and the transfer of the one or more volatile compounds of the sample to the sorbent occurs until equilibrium is reached between the sorbent and the sample. 
     
     
         12 . A system, comprising:
 a sample vial;   a sorbent configured to be placed in a headspace of the sample vial, the sorbent disposed within a tube;   means for drawing a vacuum in the sample vial; and   means for, after the vacuum is drawn in the system and while the vacuum is maintained in the system, causing transfer of one or more volatile compounds of the sample to the sorbent for subsequent chemical analysis.   
     
     
         13 . A sample extraction device, comprising:
 a port configured to accept a vacuum source; and   a sorbent coupled to the port, the sorbent disposed within a tube and configured to, after drawing, with the vacuum source, a vacuum in a system containing the sorbent and a sample, and while the vacuum is maintained in the system, cause one or more volatile compounds of the sample to transfer to the sorbent for subsequent chemical analysis including thermal desorption or solvent extraction.   
     
     
         14 . The sample extraction device of  claim 13 , wherein the system is a closed system. 
     
     
         15 . The sample extraction device of  claim 13 , wherein the system comprises a sample vial. 
     
     
         16 . The sample extraction device of  claim 13 , wherein:
 the sorbent is configured to be re-used to collect one or more volatile compounds of a second sample different from the sample after transferring the one or more volatile compounds of the sample to the sorbent for subsequent chemical analysis, and removing the one or more volatile compounds of the sample from the sorbent such that no volatile compounds remain in the sorbent.   
     
     
         17 . The sample extraction device of  claim 13 , wherein the vacuum is maintained in the system and transfer of the one or more volatile compounds of the sample to the sorbent occurs during a period of time is in the range of one minute to twenty-four hours. 
     
     
         18 . The sample extraction device of  claim 13 , wherein the vacuum is maintained in the system and at least partial transfer of the one or more volatile compounds of the sample to the sorbent occurs during a period of time is in the range of ten minutes to 16 hours. 
     
     
         19 . The sample extraction device of  claim 13 , wherein the vacuum is maintained in the system and the transfer of the one or more volatile compounds of the sample to the sorbent occurs until equilibrium is reached between the sorbent and the sample.