Multi-Laboratory Validation of a PCB Congener Method by Low-Resolution GC-MS

New Focus on Old Contaminants (e.g., lead, mercury, PCBs)
Oral Presentation

Prepared by

Contact Information: hanley.adrian@epa.gov; 202-564-1564


ABSTRACT

The only method currently approved for monitoring polychlorinated biphenyls (PCBs) in wastewater is Method 608.3, which only measures the seven common Aroclor mixtures. Most PCB contamination in the environment is highly weathered and often does not resemble the Aroclor mixtures. In addition, there are non-Aroclor sources of PCB in the environment, and Aroclor results underestimate PCB contamination in a sample compared to the analysis of PCB congeners.

EPA’s Office of Water led and completed a single-laboratory validation of a PCB congener method using low-resolution gas chromatography – mass spectrometry with select ion monitoring (GC-MS-SIM) in 2017. The method uses 29 carbon-13 labeled PCBs as extracted internal standards to quantify results for all 209 PCB congeners, with some co-eluting. EPA’s Office of Water is currently leading a multi-laboratory validation study of the method with 12 or more participating laboratories.

The goal of this project was to develop a method that can:
1. Identify and quantify PCB contamination at the congener level
2. Improve sensitivity over Method 608, but avoid problems with typical laboratory background contamination
3. Be implemented at a typical mid-sized full-service environmental laboratory

The presentation outlines the procedure, summarizes the multi-laboratory validation results, and describes the required future steps to generate an approved method for wastewater under 40 CFR Part 136.