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Semi-Quantitative Non-Targeted Analysis as a Rapid Risk Prioritization Tool: A Proof of Concept Using Activated Carbon Drinking Water Filters
Citation:
Groff, L., H. Liberatore, S. Newton, AND J. Sobus. Semi-Quantitative Non-Targeted Analysis as a Rapid Risk Prioritization Tool: A Proof of Concept Using Activated Carbon Drinking Water Filters. American Chemical Society Spring 2021 National Meeting, Virtual, NC, April 05 - 16, 2021. https://doi.org/10.23645/epacomptox.14410475
Impact/Purpose:
Presentation to the ACS Spring 2021 National Meeting in April 2021. Here, we illustrate a proof-of-concept risk-based prioritization using a mixture of 66 volatile and semi-volatile chemicals commonly found in drinking water, extracted from spiked activated carbon filters, and analyzed using GC high-resolution mass spectrometry (HRMS). Semi-quantitative concentration estimates of all 66 chemicals were determined using a regression-based model and surrogate response factors. This research serves as a model to focus larger NTA datasets on priority chemical lists for further targeted analysis and risk assessment.
Description:
For decades, targeted gas chromatography-mass spectrometry (GC-MS) methods have been used to carefully acquire measurement data in support of risk-based assessments of volatile and semi-volatile chemicals. While targeted measurements of known chemicals have supported most exposure studies, recent discoveries of new chemicals in diverse media samples have driven a shift towards broader-scope non-targeted analysis (NTA) methods. To date, NTA methods have largely produced qualitative chemical screening results with little focus on quantitative interpretations. For NTA results to be most useful in a risk-based context, multi-step methods must be developed to estimate chemical concentrations in prepared solution (i.e., sample extracts) and ultimately in the original sampled media. Furthermore, needs exist for statistically defensible error-bounding methods if NTA data are to be considered in risk-based decisions. Here, we illustrate a proof-of-concept risk-based prioritization using a mixture of 66 volatile and semi-volatile chemicals commonly found in drinking water, extracted from spiked activated carbon filters, and analyzed using GC high-resolution mass spectrometry (HRMS). Semi-quantitative concentration estimates of all 66 chemicals were determined using a regression-based model and surrogate response factors. Statistically defensible error bounds taken from a normalized response factor distribution were applied to prepared solution concentration estimates. Media concentrations were derived from the solution estimates using percent recovery from carbon filter extract data, and compared to existing regulatory levels as a means of preliminary prioritization. This research serves as a model to focus larger NTA datasets on priority chemical lists for further targeted analysis and risk assessment. The views expressed are those of the author(s) and do not necessarily reflect the views or policies of the US EPA.
URLs/Downloads:
DOI: Semi-Quantitative Non-Targeted Analysis as a Rapid Risk Prioritization Tool: A Proof of Concept Using Activated Carbon Drinking Water Filters
LCGROFF-SEMIQUANTNTA-GCHRMSBRITA-ACS.PDF (PDF, NA pp, 5103.257 KB, about PDF)