In 2014, the Marcellus Shale Coalition (MSC) Dissolved Methane Method Workgroup commissioned a round-robin study of dissolved light gas analysis. In this initial phase, fourteen commercial and one government laboratory analyzed blind groundwater samples that had been collected at two locations. The study identified significant variation among the results, with dissolved methane values that varied from 7,440 to 34,600 µg/L for a single sample location. The study showcased the need for a more robust and consistent analytical procedure and the need for additional work to identify the source of the variability.
In 2016, the MSC commissioned a second study, again using fifteen laboratories. Four reference standards were submitted blind and analyzed by each laboratory for dissolved methane. The results of this second study will be presented starting with study design, reference standard preparation, data analysis, and the conclusion that calibration is the primary source of error. Techniques within the calibration process will be discussed relative to the source of error for analysis of dissolved methane, as well as recommendations for data users and the analytical laboratory community.

Primary Author:
David Gratson
Associate Principal of Chemistry
Environmental Standards, Inc.
Valley Forge, Pennsylvania

Conference Presenter:
Lydia Work
Environmental Standards, Inc.
Valley Forge, Pennsylvania

Co-Authors:
Rock Vitale, Lydia Work, Stephen Brower, and the Marcellus Shale Coalition Environmental Standards, Inc.