Andrew McEachran

Andrew McEachran
Agilent · Mass Spectrometry Division

MS, PhD

About

49
Publications
9,110
Reads
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1,386
Citations
Introduction
I am a Product Owner at Agilent Technologies leading the development of software for managing mass spectral libraries and databases.
Additional affiliations
February 2019 - present
Agilent
Position
  • Researcher
June 2016 - February 2019
United States Environmental Protection Agency
Position
  • PostDoc Position
June 2013 - June 2016
North Carolina State University
Position
  • Research Assistant
Education
June 2013 - August 2016
August 2011 - May 2013
Texas Tech University
Field of study
  • Environmental Toxicology
August 2007 - May 2011
North Carolina State University
Field of study
  • Environmental Technology and Management

Publications

Publications (49)
Article
Full-text available
Chemical database searching has become a fixture in many non-targeted identification workflows based on high-resolution mass spectrometry (HRMS). However, the form of a chemical structure observed in HRMS does not always match the form stored in a database (e.g., the neutral form versus a salt; one component of a mixture rather than the mixture for...
Article
Full-text available
Tens-of-thousands of chemicals are registered in the U.S. for use in countless processes and products. Recent evidence suggests that many of these chemicals are measureable in environmental and/or biological systems, indicating the potential for widespread exposures. Traditional public health research tools, including in vivo studies and targeted a...
Article
Monitored contaminants in drinking water represent a small portion of the total compounds present, many of which may be relevant to human health. To understand the totality of human exposure to compounds in drinking water, broader monitoring methods are imperative. In an effort to more fully characterize the drinking water exposome, point-of-use wa...
Article
Chemical features observed using high-resolution mass spectrometry can be tentatively identified using online chemical reference databases by searching molecular formulae and monoisotopic masses and then rank-ordering of the hits using appropriate relevance criteria. The most likely candidate “known unknowns,” which are those chemicals unknown to a...
Article
Full-text available
Emergence and spread of antibiotic resistance has become a global health threat and is often linked with overuse and misuse of clinical and veterinary chemotherapeutic agents. Modern industrial-scale animal feeding operations rely extensively on veterinary pharmaceuticals, including antibiotics, to augment animal growth. Following excretion, antibi...
Preprint
Background: The NORMAN Association (https://www.norman-network.com/) initiated the NORMAN Suspect List Exchange (NORMAN-SLE; https://www.norman-network.com/nds/SLE/) in 2015, following the NORMAN collaborative trial on non-target screening of environmental water samples by mass spectrometry. Since then, this exchange of information on chemicals tha...
Article
Non-targeted analysis (NTA) encompasses a rapidly evolving set of mass spectrometry techniques aimed at characterizing the chemical composition of complex samples, identifying unknown compounds, and/or classifying samples, without prior knowledge regarding the chemical content of the samples. Recent advances in NTA are the result of improved and mo...
Article
With the increasing availability of high-resolution mass spectrometers, suspect screening and non-targeted analysis are becoming popular compound identification tools for environmental researchers. Samples of interest often contain a large (unknown) number of chemicals spanning the detectable mass range of the instrument. In an effort to separate t...
Article
There is an increasing need for comparable and harmonized retention times (tR) in liquid chromatography (LC) among different laboratories, to provide supplementary evidence for the identity of compounds in high-resolution mass spectrometry (HRMS)-based suspect and nontarget screening investigations. In this study, a rigorously tested, flexible, and...
Article
Full-text available
Software applications for high resolution mass spectrometry (HRMS)-based non-targeted analysis (NTA) continue to enhance chemical identification capabilities. Given the variety of available applications, determining the most fit-for-purpose tools and workflows can be difficult. The Critical Assessment of Small Molecule Identification (CASMI) contes...
Article
Full-text available
High-resolution mass spectrometry (HRMS) enables rapid chemical annotation via accurate mass measurements and matching of experimentally derived spectra with reference spectra. Reference libraries are generated from chemical standards and are therefore limited in size relative to known chemical space. To address this limitation, in silico spectra (...
Article
Full-text available
Confident identification of unknown chemicals in high resolution mass spectrometry (HRMS) screening studies requires cohesive workflows and complementary data, tools, and software. Chemistry databases, screening libraries, and chemical metadata have become fixtures in identification workflows. To increase confidence in compound identifications, the...
Article
Full-text available
Particulate matter (PM) emitted from beef cattle feedyards transports manure-affiliated compounds including antibiotics and steroids from feedyards into the surrounding environment. Similarly, commercial dairy operations have the potential to release PM, comprised largely of aerosolized manure, into the surrounding environment along with associated...
Article
Non-targeted analysis (NTA) methods are increasingly used to discover contaminants of emerging concern (CECs), but the extent to which these methods can support exposure and health studies remains to be determined. EPA’s Non-Targeted Analysis Collaborative Trial (ENTACT) was launched in 2016 to address this need. As part of ENTACT, 1269 unique subs...
Presentation
Full-text available
High resolution mass spectrometry (HRMS) and non-targeted analysis (NTA) are advancing the identification of emerging contaminants in environmental and agricultural matrices. However, confidence in structure identification of unknowns in NTA presents challenges to analytical chemists. Structure identification requires integration of complementary d...
Presentation
Full-text available
High resolution mass spectrometry (HRMS) and non-targeted analysis (NTA) are improving the means by which exposure analyses can be conducted by advancing the identification of emerging contaminants in environmental and biological matrices. Confident identification in NTA requires cohesive workflows that combine high performance instrumental analysi...
Poster
Full-text available
Non-targeted and suspect screening studies using high resolution mass spectrometry (HRMS) have revolutionized how chemicals are detected in complex matrices. However, data processing remains challenging due to the vast number of chemicals detected in samples, software and computational requirements of data processing, and inherent uncertainty in co...
Article
Full-text available
Forest-water reuse (FWR) systems treat municipal, industrial, and agricultural wastewaters via land application to forest soils. Previous studies have shown that both large-scale conventional wastewater treatment plants (WWTPs) and FWR systems do not completely remove many contaminants of emerging concern (CECs) before release of treated wastewater...
Presentation
Full-text available
Identification of unknowns in mass spectrometry based non-targeted analyses (NTA) requires the integration of complementary pieces of data to arrive at a confident, consensus structure. Researchers use chemical reference databases, spectral matching, fragment prediction tools, retention time prediction tools, and a variety of other data to arrive a...
Presentation
Full-text available
EPA’s National Center for Computational Toxicology is developing automated workflows for curating large databases and providing accurate linkages of data to chemical structures, exposure and hazard information. The data are being made available via the EPA’s CompTox Chemistry Dashboard (https://comptox.epa.gov/dashboard), a publicly accessible webs...
Presentation
Full-text available
Researchers at EPA’s National Center for Computational Toxicology integrate advances in biology, chemistry, and computer science to examine the toxicity of chemicals and help prioritize chemicals for further research based on potential human health risks. The goal of this research program is to quickly evaluate thousands of chemicals, but at a much...
Article
Full-text available
A two-dimensional gas chromatography-time of flight/mass spectrometry (GC×GC-TOF/MS) suspect screening analysis method was used to rapidly characterize chemicals in 100 consumer products – which included formulations (e.g., shampoos, paints), articles (e.g., upholsteries, shower curtains), and foods (cereals) – and therefore supports broader effort...
Article
High-resolution mass spectrometry (HRMS) data has revolutionized the identification of environmental contaminants through non-targeted analysis (NTA). However, chemical identification remains challenging due to the vast number of unknown molecular features typically observed in environmental samples. Advanced data processing techniques are required...
Article
Full-text available
Despite an abundance of online databases providing access to chemical data, there is increasing demand for high-quality, structure-curated, open data to meet the various needs of the environmental sciences and computational toxicology communities. The U.S. Environmental Protection Agency’s (EPA) web-based CompTox Chemistry Dashboard is addressing t...
Presentation
Full-text available
Non-targeted analysis (NTA) workflows in high-resolution mass spectrometry require mechanisms for compound identification. One strategy for tentative identification is the use of online chemical databases such as ChemSpider. Databases like this use molecular formulae and monoisotopic mass-based searching and rank-ordering of results by the associat...
Poster
Full-text available
The U.S. Environmental Protection Agency (EPA) Computational Toxicology Program integrates advances in biology, chemistry, and computer science to help prioritize chemicals for further research based on potential human health risks. This work involves computational and data driven approaches that integrate chemistry, exposure and biological data. T...
Presentation
Full-text available
The U.S. Environmental Protection Agency (EPA) Computational Toxicology Program integrates advances in biology, chemistry, and computer science to help prioritize chemicals for further research based on potential human health risks. This work involves computational and data driven approaches that integrate chemistry, exposure and biological data. A...
Poster
Full-text available
The EPA’s National Center of Computational Toxicology (NCCT) Chemistry Dashboard provides access to chemistry data for about 720,000 chemical substances. The application is used to source, for example, physicochemical property data, bioassay screening data and functional use and product composition data. The dashboard provides access to a number of...
Poster
Full-text available
The CompTox Chemistry Dashboard is a publicly accessible database provided by the National Center for Computational Toxicology at the US-EPA. The Dashboard provides access to a database containing ~750,000 chemicals and integrates a number of our public-facing projects (e.g. ToxCast and ExpoCast). The available data provide a valuable foundation to...
Article
Forest-water reuse systems infiltrate municipal, industrial, and agricultural wastewaters through forest soils to shallow aquifers that ultimately discharge to surface waters. Their ability to mitigate regulated nutrients, metals, and organic chemicals is well known, but the fate of non-regulated chemicals in these systems is largely unstudied. Thi...
Presentation
Full-text available
There is a growing need for rapid chemical screening and prioritization to inform regulatory decision-making on thousands of chemicals in the environment. We have previously used high-resolution mass spectrometry to examine household vacuum dust samples using liquid chromatography time-of-flight mass spectrometry (LC-TOF/MS). Using a combination of...
Presentation
Full-text available
The iCSS Chemistry Dashboard is a publicly accessible dashboard provided by the National Center for Computation Toxicology at the US-EPA. It serves a number of purposes, including providing a chemistry database underpinning many of our public-facing projects (e.g. ToxCast and ExpoCast). The available data and searches provide a valuable path to str...
Article
Full-text available
The occurrence and fate of pharmaceutical and personal care products in the environment are of increasing public importance due to their ubiquitous nature and documented effects on wildlife, ecosystems, and potentially humans. One potential, yet undefined, source of entry of pharmaceuticals into the environment is via the land application of munici...
Article
Steroid growth promoters are commonly administered to beef cattle residing on feedyards, and a portion of these compounds are excreted in manure along with endogenous steroids. Steroids associated with aerosolized particulate matter (PM) can be transported from feedyards via wind. To assess potential androgenic and estrogenic activity of PM extract...

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Cited By

Projects

Projects (5)
Project
Suspect screening analysis (SSA) methods and non-targeted analysis (NTA) methods offer unique means to screen for xenobiotic chemicals in a variety of environmental and biological media. However, there are few, if any, analysis and reporting standards for studies utilizing SSA and NTA methods. This project uses known standards and samples to characterize the abilities of SSA and NTA methods.
Project
Cheminformatics tools and data delivered via cheminformatics integration paths are increasingly important to support mass spectrometry, especially in regards to suspect screening and non-targeted analysis. This project will be a container for our efforts to support mass spectrometry through the delivery of data, applications and programmatic interfaces to both.
Project
To date, forest water reuse systems are an undefined source of entry of regulated and non-regulated organic chemicals to groundwater and surface waters. This project will engage participatory community science to evaluate the presence, fate, transport, and human health risks of these organic chemicals in a watershed-scale forest water reuse system that has received secondary wastewater irrigation for almost two decades.