Targeted and Nontargeted Detection and Characterization of Trace Organic Chemicals in Human Serum and Plasma Using QuEChERS Extraction

Abstract

Humans are exposed to a broad range of organic chemicals. Although targeted gas chromatography mass spectrometry techniques are used to quantify a limited number of persistent organic pollutants and trace organic contaminants in biological samples, nontargeted, high-resolution mass spectrometry (HRMS) methods assess the human exposome more extensively. We present a QuEChERS extraction for targeted and nontargeted analysis of trace organic contaminants using HRMS and compare this method to a traditional, cartridge-based solid-phase extraction (SPE). Following validation using reference and spiked serum samples, the method was applied to plasma samples (n = 75) from the Prospective investigation of Obesity, Energy, and Metabolism (POEM) study. We quantified 44 analytes using targeted analysis and 6247 peaks were detected using the nontargeted approach. Over 90% of targeted analytes were at least 90% recovered using the QuEChERS method in spiked serum samples. In nontargeted analysis, 84% of the peaks were above the method detection limit with area counts up to 3.0 × 105 times greater using the QuEChERS method. Of the targeted compounds, 88% were also identified in the nontargeted analysis. We categorized the 4212 chemicals assigned an identity in using EPA’s CompTox Dashboard and 1076 chemicals were found in at least one list. The category with the highest number of chemicals was “androgen or estrogen receptor activity.” The findings demonstrate that a QuEChERS technique is suitable for both targeted and nontargeted analysis of trace organic contaminants in biological samples.

Environmentally relevant uptake, elimination, and metabolic changes following early embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish

“…The 50 ppt dose has been established as a sublethal concentration in embryonic and juvenile zebrafish ( King Heiden et al, 2009 ; Baker et al, 2013 ; Steenland et al, 2001 ; Ruby et al, 2002 ) and used to model transgenerational effects of TCDD exposure. Changes in cardiac dysfunction have been reported as early as 60 hpf in the 1 and 10 ppb TCDD-exposed embryos; however, cardiac collapse and overt morphological malformations occur later in development and culminate in death between 5- and 7-days post fertilization (dpf ( Choudhary et al, 2015 ; Place et al, 2021 ; Hill et al, 2003 ; Yin et al, 2008 ; Manz et al, 2021 ),). Therefore, to avoid the complications associated with organ dysfunction and overt morphological malformations, we selected 24, 48, and 72 hpf as our time points of interest for both the body burden and metabolomic studies.…”

“…Embryos were extracted and measured for TCDD concentrations by GC-HRMS ( Manz et al, 2021 ). Briefly, pooled embryos were transferred into an amber glass 4-dram vial with 4 mL 1:1:1 hexane:acetone:dichloromethane.…”

“…To address this critical data gap, we used gas chromatography (GC) high-resolution mass spectrometry (HRMS) to quantify TCDD absorption in zebrafish embryos and non-targeted liquid chromatography (LC) HRMS metabolomics to understand the uptake and elimination dynamics in embryonic and larval zebrafish as well as how TCDD exposure during early embryogenesis affects the metabolome. Non-targeted HRMS analysis is an unbiased, discovery-based approach for characterizing the chemical composition of a sample without a priori knowledge ( Place et al, 2021 ; Manz et al, 2022 ). By using this approach, we are able to determine whether pathways that have been previously shown to be affected by TCDD exposure in mammals are also affected by exposure in fish.…”

Cross-species metabolomic analysis of tau- and DDT-related toxicity

“…Prior to extraction, each sample was spiked with labeled isotope internal standards to assess analyte recovery. Each sample was extracted using QuEChERS (Quick, Easy, Cheap, Effective, Rugged, Safe) ( 40 ). The samples were first vortex mixed in centrifuge tubes with 1 mL 1:1:1 hexane:acetone:dichloromethane and sonicated for 30 min.…”

High-resolution mass spectrometry reveals environmentally relevant uptake, elimination, and metabolic alterations following early embryonic exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin in zebrafish

“…Quantification of TCDD: Embryos were extracted and measured for TCDD concentrations by GC-HRMS (39). Briefly, pooled embryos were transferred into an amber glass 4-dram vial with 4 mL 1:1:1 hexane:acetone:dichloromethane.…”