Air Sampling

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Revision as of 03:38, 24 September 2020 by Jwelker (talk | contribs) (→‎X-Sorber)
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X-Sorber

Xsorber2.jpg

The X-Sorber is a lightweight sampling device that can be returned to its host instrument for sample desorption, data download, conditioning, and charging.

System Overview Features

  • Safe air sampling using dual selectable sorbent tubes
  • Storage of sample information including GPS coordinates, time and date, sample duration and volume, user ID, and tube ID
  • Thermal desorption and sample analysis capabilities
  • Sorbent tube conditioning at the air dock

Sampling and Desorption

  • activation of the sample pump pulls air through the installed sorbent tubes upon which the sample is collected
  • the sorben tube is loaded with the sample's constituent compounds
  • upon docking the X-Sorber to the host instrument, the inlet and appropriate sorbent tube are heated. Carrier gas is then routed in the opposite direction through the flow path, and the desorbed sample components are carried into the GCMS.
  • analytes are adsorbed to the sorbent tube until they cross the breakthrough volume's threshold, causing them to break through the downstream end of the tube.
  • sample collection below the breakthrough volume's threshold allows for proper calculation of the analyte's concentration

Air Dock System Two dock ports

  • Universal Sampling Port: the main docking port
  • Conditioning Port: can be used for programming and conditioning, but will not transfer samples into the GCMS

Programming at the GCMS

  • sample methods must be programmed at the GCMS using Griffin System Software and must be downloaded on the X-Sorber prior to field use

Conditioning

  • The sorbent tube is heated and a controlled flow of carrier gas is used to desorb any remaining chemical residue

Tube Constraints

  • a maximum of 20 sorbent tube IDs can be recorded on the X-Sorber
  • 10 pre-programmed methods are available
  • each sorbent tube is allowed 10 sample runs before becoming "maxed"
  • tubes should be conditioned and desorbed as close in time to deployment as possible
  • tube lifespans will vary according to sorbent bed material and use

Programming the X-Sorber

  • open griffin system software
  • go to file/new/X-Sorber
  • 40 degrees celsius is the threshold above which a sample will not run
  • flow rate: fasater flow rate may capture a target chemical of lower concentration, but may cause analyte breakthrough. 150-675 mL/min
  • single tube:325-675
  • multi tube:150-350

Inlet Cap

  • inlet cap should be placed over the sampling inlet to cover the pneumatic and electrical ports