Effects of Background Alcohols on the Analysis of Low Level Volatile Organic Compounds in Air by EPA Method TO-15 While Performing Vapor Intrusion Investigations

Oral Presentation

Prepared by A. Rezendes, W. Elcoate
Alpha Analytical, Inc., 277 Boulder Drive, Dublin, NH, 03444, United States


Contact Information: andrez@alphalab.com; 508-844-4181


ABSTRACT

Alcohols are used in a wide range of products and are intermediate compounds in metabolic processes. Although as a group they have a range of health effects typically these effects are at higher concentrations and they are not known as carcinogens. Many of the low molecular weight alcohols have sufficient volatility to be collected and recovered from passivated canisters. The detection limits for these compounds can be in the low and sub-ppbv ranges. They also can present some chromatographic challenges depending on concentrations and other compounds of interest that maybe present.
Vapor Intrusion (VI) investigations is currently an area of significant regulatory attention that may require the analysis of a wide range of Volatile Organic Compounds. Published data and Alpha’s experience is that alcohols show up routinely in the analysis of indoor air samples, both residential & commercial. They are also seen in ambient air and sub-surface gas samples. IPA has been incorporated into many vapor intrusion guidance’s as a leak check compound: It has shown up in samples with significant impact on the ability to report usable data.

The presentation will illustrate potential sources for alcohols including natural, they use in additives and their prevalence in many products used in everyday life. Some alcohols are target analytes of interest for these investigations. Using available data and resources the presentation discusses the background and analysis of samples for VI Investigations. Examples will be given of where the presence of alcohols have impacted reported data and the steps that were taken to report data that meets the project DQO’s.

Whether targeted or not, expected or not, alcohols show up and can have a significant impact on the laboratories’ ability to report data at meet specific data quality objectives. These data reported are used to determine health risk exposure and their presence can affect the ability of the investigator to make these determinations.