Factors Affecting Sampling Strategies for Design of an Effects‐Directed Analysis for Endocrine‐Active Chemicals

Abstract

Effects‐directed analysis (EDA) is an important tool for identifying unknown bioactive components in a complex mixture. Such an analysis of endocrine‐active chemicals (EACs) from water sources has promising regulatory implications but also unique logistical challenges. We propose a conceptual EDA (framework) based on a critical review of EDA literature and concentrations of common EACs in waste and surface waters. Required water volumes for identification of EACs under this EDA framework were estimated based on bioassay performance (in vitro and in vivo bioassays), limits of quantification by mass spectrometry (MS), and EAC water concentrations. Sample volumes for EDA across the EACs showed high variation in the bioassay detectors, with genistein, bisphenol A, and androstenedione requiring very high sample volumes and ethinylestradiol and 17β‐trenbolone requiring low sample volumes. Sample volume based on the MS detector was far less variable across the EACs. The EDA framework equation was rearranged to calculate detector “thresholds,” and these thresholds were compared with the literature EAC water concentrations to evaluate the feasibility of the EDA framework. In the majority of instances, feasibility of the EDA was limited by the bioassay, not MS detection. Mixed model analysis showed that the volumes required for a successful EDA were affected by the potentially responsible EAC, detection methods, and the water source type, with detection method having the greatest effect on the EDA of estrogens and androgens. The EDA framework, equation, and model we present provide a valuable tool for designing a successful EDA. Environ Toxicol Chem 2020;39:1309–1324. © 2020 SETAC

Identifying Chemicals and Mixtures of Potential Biological Concern Detected in Passive Samplers from Great Lakes Tributaries Using High‐Throughput Data and Biological Pathways

“…Samplers such as the semipermeable membrane device (SPMD) and the polar organic chemical integrative sampler (POCIS) can provide data on the time‐weighted average concentration of select chemicals in the water column, which can be a reasonable estimate of an organism's exposure to dissolved chemicals (Huckins et al 2006 ). Extracts from SPMDs and POCIS have frequently been screened by in vitro (e.g., estrogen assays, ethoxyresorufin‐O‐deethylase (EROD), Microtox, vitellogenin induction, Ames, and effects‐directed analysis studies) and in vivo (e.g., tadpole development, fish injections) tests to identify biological effects related to exposure to a chemical or mixture of chemicals (Parrott and Tillitt 1997 ; Petty et al 2000 ; Bridges et al 2004 ; Johnson et al 2004 ; Rastall et al 2004 ; Vermeirssen et al 2005 ; Alvarez et al 2008 , 2013 ; Brennan et al 2020 ).…”

Substances of emerging concern in Baltic Sea water: Review on methodological advances for the environmental assessment and proposal for future monitoring

“…Identification of toxic compounds in individual fractions is mainly performed using targeted, but also non-targeted or suspect MS methods (Hollender et al 2019 ). For example, Brennan et al ( 2020 ) proposed a strategy to design EDA for the analysis of endocrine-active compounds in water in combination with liquid chromatography (LC)-based fractionation and mass spectrometric analysis and Tufi et al ( 2016 ) reported on the identification of AChE inhibitors in surface water through an EDA approach.…”

Targeted Selecting of Bioassay Methods as an Alternative to the “Battery of Bioassays”

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