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Enhancing EPA Method TO-15 Using TOF-MS to Address High Matrix Effects in Soil Gas

Event Announcement

Tuesday, Jul 16, 2019

 

About This Webinar:

Vapor intrusion (VI) investigations often rely on volatile organic compound (VOC) measurements in soil gas to evaluate potential inhalation risks to occupants of overlying/nearby buildings. While EPA Method TO-15 typically can be configured to achieve required sub-part per billion by volume (ppbv) risk-based screening levels, soil vapor may contain high levels of interfering matrix compounds, requiring dilution to minimize gross contamination of the analytical instrumentation.These dilutions can result in elevated reporting limits for analytes of interest, sometimes with reporting limits for non-detect compounds that are higher than the risk-based screening levels. In addition to impeding achievement of data quality objectives, high concentrations of co-eluting matrix peaks can also confound the identification and accurate quantification of these target chemicals.

Eurofins Air Toxics has configured and validated an innovative technique to measure trace concentrations of selected VOCs in high concentration matrices, utilizing conventional TO-15 canister sample collection and a standard TO-15 air concentrator. To remove interfering peaks and isolate targeted VOCs, a custom multidimensional gas chromatographic system is utilized.

Compound detection is achieved using a Time-of-Flight mass spectrometer (TOF-MS) which provided improved sensitivity and selectivity as compared to a conventional quadrupole mass spectrometer. This specialized TO-15 configuration has allowed the laboratory to analyze samples with high matrix interference without dilution and has provided reporting limits required to effectively assess risk and support decisions for closure of “matrix-challenged” sites.

Topics The Presentation Will Cover Include:

  • Brief description and limitations of conventional TO-14A/TO-15 methods, including
    • Routinely used analytical detectors
    • Available sample clean-up techniques
  • In depth description of High Selectivity/High Sensitivity (HSS) TO-15 configuration
    • How does it differ from conventional TO-14A/TO-15?
  • Case Study: Quantifying Lead Scavengers Ethylene Dibromide (EDB) and Ethylene Dichloride (EDC) at Petroleum Impacted Sites
    • Validation against EPA TO-15 Performance Criteria
    • Gasoline Matrix validation
    • Field Sample Performance
      • TO-15 HSS vs. conventional TO-15
        • Reporting limits
        • Compound identification
  • Other TO-15 HSS applications and case studies

Who Should Attend?

  • Consultants and Engineers
  • Regulatory Officials
  • Commercial and Industrial Stakeholders

A question and answer session will immediately follow the presentation. At the conclusion of each webinar, you will be asked for your feedback and opinions for future webinar topics to be developed by Eurofins Air Toxics and Eurofins TestAmerica.

July 16, 2019