Use of On-Site GC/MS Analysis to Distinguish between Vapor Intrusion and Indoor Sources of VOCs
ER-201119
Objective
Distinguishing between vapor intrusion and indoor sources of volatile organic compounds (VOCs) is a significant challenge in site assessments, greatly increasing the cost and complexity of investigations. Rapid on-site analysis of indoor air samples using a gas chromatograph/mass spectrometer (GC/MS) enables users to understand the distribution of VOCs in real-time, supporting a real-time identification of the source. This project will demonstrate the application of a field-portable HAPSITE GC/MS to distinguish between vapor intrusion and indoor sources of VOCs.
Technology Description
GC/MS is the gold standard for the quantitative analysis of samples containing VOCs or other organic compounds. Gas chromatography provides separation of a wide range of chemicals that may be present in a single sample. Following separation, the compounds are sent through a mass spectrometer that provides definitive identification of each compound in the sample. The HAPSITE GC/MS is a field portable instrument designed for on-site analysis of air and water samples by personnel without extensive training in analytical chemistry. The HAPSITE is intended to be transported from site to site in a suitcase-sized shipping container. The user interface is relatively simple so that the proper use of the instrument requires only a few days of training. When operated in the quantitative GC/MS mode, the HAPSITE can accurately measure VOCs present in air samples at concentrations as low as 1 µg/m3.
Benefits
When indoor air testing is conducted, VOCs are commonly detected at concentrations above the applicable indoor air screening criteria. Such results often require extensive follow-up testing to definitively identify the source of the detected VOCs. At Hill Air Force Base, for example, most of the trichloroethene (TCE), tetrachloroethene (PCE), and 1,2-dichloroethane (1,2-DCA) detections above regulatory action levels in indoor air have subsequently been attributed to indoor sources of VOCs rather than vapor intrusion. However, identification of the indoor VOC source has typically required multiple rounds of sampling and analysis, and, in many cases, an indoor source is identified only after a vapor intrusion mitigation system has been installed and has failed to improve indoor air quality. The development of a validated standard protocol for use of the HAPSITE GC/MS to distinguish between vapor intrusion and indoor sources of VOCs in buildings with vapor intrusion concerns could reduce vapor intrusion investigation costs by 50% or more by significantly reducing the need for follow-up investigation at buildings with exceedances of indoor air screening levels due to indoor sources of VOCs. (Anticipated Project Completion - 2014)
Points of Contact
Principal Investigator
Dr. Thomas McHugh
GSI Environmental Inc.
Phone: 713-522-6300
Fax: 713-522-8010
Document Types
- Fact Sheet - Brief project summary with links to related documents and points of contact.
- Final Report - Comprehensive report for every completed SERDP and ESTCP project that contains all technical results.
- Cost & Performance Report - Overview of ESTCP demonstration activities, results, and conclusions, standardized to facilitate implementation decisions.
- Technical Report - Additional interim reports, laboratory reports, demonstration reports, and technology survey reports.
- Guidance - Instructional information on technical topics such as protocols and user’s guides.
- Workshop Report - Summary of workshop discussion and findings.
- Multimedia - On demand videos, animations, and webcasts highlighting featured initiatives or technologies.
- Model/Software - Computer programs and applications available for download.
- Database - Digitally organized collection of data available to search and access.