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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 (QSAR 2021)
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 (QSAR 2021). QSAR 2021 International Workshop on QSAR in Environmental and Health Sciences, Virtual, NC, June 07 - 10, 2021. https://doi.org/10.23645/epacomptox.22550044
Impact/Purpose:
Presentation to the QSAR 2021 International Workshop on QSAR in Environmental and Health Sciences June 2021
Description:
For decades, targeted gas chromatography-mass spectrometry (GC-MS) methods have been used to 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, discoveries of new chemicals in diverse media samples have driven a shift towards broader-scope non-targeted analysis (NTA) methods. Typical NTA methods have largely produced qualitative chemical screening results with minimal quantitative interpretation. For NTA results to be most useful in a risk-based context, multi-step methods must be developed to estimate chemical concentrations in prepared 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/semi-volatile chemicals commonly found in drinking water, extracted from spiked activated carbon filters, and analyzed using GC high-resolution mass spectrometry. Semi-quantitative concentration estimates of all 66 chemicals were determined using regression-based modeling 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 solution estimates using percent recovery data from carbon filter extracts, and compared to existing regulatory levels for 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 (QSAR 2021)
LCGROFF-SEMIQUANTNTA-GCHRMSBRITA-QSAR2021.PDF (PDF, NA pp, 5121.796 KB, about PDF)