ISIAQ STC 11 (Sources, Monitoring and Evaluation: Chemical Pollutants) have hosted webinars to

increase communication within the STC11 and expanding our outreach. The upcoming webinar will be

on the topic of “New instrumentation/monitoring techniques for faster knowledge”. Below is the

webinar information. Please mark your calendar and join us to learn more!

 

Date: February 13th, 2020 • 9:00‐10:00 am. U.S. Eastern Standard Time

Outlines: Presentations (2×20minutes) and Discussions (20 minutes)

Presentation 1: Non‐Targeted Analysis Approaches in Environmental Chemistry

 

Presenter: Dr. James McCord is a Chemist in the Multimedia Methods Branch of the Environmental

Protection Agency. He received a PhD in analytical chemistry, with a minor in molecular biotechnology

from North Carolina State University. Dr. McCord’s specialty is in high‐resolution mass spectrometry

analysis of biological and environmental samples, with a focus on non‐targeted analysis, compound

discovery, and structural determination by mass spectrometry. His research focus is centered on

developing methods for non‐targeted analysis, automated screening and (semi‐)quantitation of

environmental chemicals. He also works on the identification and structural elucidation of emerging

environmental contaminants, such as per‐ and polyfluorinated alkyl substances (PFAS). For the past

several years, James has been leading analyst on state/regional PFAS projects in ORD, including the

GenX response in NC and ongoing studies in soil, water, air, and biota nationwide.

 

Abstract: Environmental exposure research has long revolved around targeted analysis of chemicals of

interest, generally relying on analytical standards and well understood chemical processes. In recent

years, technological advances have allowed the development of non‐targeted methods, whereby the

entire composition of a sample can be described and ultimately linked to human exposure,

epidemiology and/or toxicological outcomes. These techniques primarily revolve around high resolution

mass spectrometry (HRMS), specifically time‐of‐flight and Orbitrap mass spectrometers, for novel

compounds discovery and description. HRMS data can reveal unanticipated chemical species in all

manner of samples, while providing empirical chemical formulas, chemical class‐based assignments, and

potentially fully resolved structural information from MS/MS experiments. These instruments also

enable high‐throughput screening of complex samples against established databases of empirical data

collected from prior samples and/or reference chemical species. This talk will focus on general

experimental design in non‐targeted analysis (NTA) as well as high‐resolution mass spectrometry

instrumentation and data interpretation approaches in an environmental chemistry context.

Presentation 2: Evaluation of in silico MS/MS spectra in Non‐Targeted Analysis Workflows

 

Presenter: Mr. Alex Chao is a chemist working in the Center for Computational Toxicology & Exposure at

the U.S. Environmental Protection Agency. His professional background is in liquid chromatography

mass spectrometry based method development and validation for small molecule targets. He received

his Master’s in Chemistry from the University of North Carolina at Chapel Hill performing research

utilizing high resolution mass spectrometry to characterize enzymatic functions within algae systems. His

current work at the EPA is focused on developing non targeted analysis workflows utilizing high

resolution mass spectrometry and computational tools in order to characterize exposures from both

internal and external environments.

 

Abstract: Advancements in analytical technologies have allowed a shift from targeted monitoring

methods to non‐targeted analysis (NTA) methods to support chemical exposure assessments. Highresolution

mass spectrometry (HRMS) platforms can now generate data of sufficient quality to identify

chemicals post‐acquisition (i.e., without a priori knowledge of presence or absence), but require

sufficient advances in computational tools and databases for proper interpretation. Confident NTA

identifications are made through accurate mass measurements and matching of experimentally derived

spectra with reference spectra, yet reference libraries are limited in size relative to the known chemical

universe. In silico spectra have therefore been predicted via Competitive Fragmentation Modeling‐ID

(CFM‐ID) algorithms for compounds within the U.S. Environmental Protection Agency’s (EPA) Distributed

Structure‐Searchable Toxicity (DSSTox) database. DSSTox contains approximately 875,000 substances,

allowing a substantial increase in the number of chemicals for which high‐quality fragmentation data

can be interpreted. This presentation will cover the utilization of CFM‐ID predicted spectra as part of a

larger NTA workflow. The goals of this work are to enable rapid and confident chemical identifications in

a variety of environmental and biological media to support efficient risk‐based chemical prioritizations.

Participation:

– Online meeting ID: isiaq

– Join the online meeting: https://join.startmeeting.com/isiaq (you may need to download the

APP to watch presentation slides, ask questions, and participate in discussions).

– Dial‐in number (US): (701) 801‐1211 Access code: 228‐441‐045#

– International dial‐in numbers: https://stme.in/i/isiaq

We encourage you to invite your colleagues who might be interested in this topic, and we hope you can

make it!

 

Best regards,

Ying Xu (STC 11 Chair, Tsinghua University, China and The University of Texas at Austin, U.S.A.)

Dustin Poppendieck (STC 11 Vice Chair, National Institute of Standards and Technology, U.S.A.)

Xiaoyu Liu (STC 11 Secretary, Environmental Protection Agency, U.S.A.)