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What's the Bottom Line
Citation:
Glassmeyer, S., A. Batt, D. Kolpin, AND E. Furlong. What's the Bottom Line. SETAC 2016, Orlando, FL, November 06 - 10, 2016.
Impact/Purpose:
Presented research findings to SETAC audience
Description:
Advances in analytical instrumentation have not only increased the number and types of chemicals measured, but reduced the quantitation limits, allowing these chemicals to be detected at progressively lower concentrations in various environmental matrices. Such analytical advancements have been a particular benefit to pharmaceuticals, hormones, personal care products and other contaminants of emerging concern (CECs). Nevertheless, even as specific methods for CECs are being developed concentrations of many CECs are still near or below the threshold of these improved detection limits. The complexity of these analyses is further compounded by the fact that many CECs are so pervasive in that they may be present in the environments in which samples are collected, processed, or analyzed and may contaminate samples. To ensure confidence in data being generated, an integrated suite of quality assurance (QA) procedures and quality control (QC) samples are necessary. These QA procedures and QC samples prevent or address potential for contamination or loss in both the field and the laboratory, and discriminate between field or laboratory introduction of these artifacts. These QC samples include, but are not limited to, field and laboratory blanks, replicate samples, matrix fortified samples, fortified laboratory samples and instrument blanks. This presentation will examine the QA protocols implemented in and QC sample results from a recent national study of drinking water treatment plants across the United States jointly conducted by the USEPA and the USGS. The QA/QC implemented in this project resulted in nearly a third of the measurements demoted to qualitative instead of quantitative detections, and another third completely censored due to contamination or method performance issues. The presentation will also examine how the handling of detections hovering near the threshold of detection influences the data set.
