Webinar: Regioisomer Differentiation for Substances Using GC-IR [Archival]

Webinar: Regioisomer Differentiation for Substances Using GC-IR [Archival]


Forensic examiners are called upon to conduct detailed chemical analyses of drugs, precursors, and related chemicals that may be present with imposter substances, isomers, or other compounds that may interfere with analysis. Gas chromotograph mass spectrometry (GCMS) has been the analytical instrument of choice for these analyses, but GCMS may not distinguish among many drug substances and related chemicals. Dr. Randall Clark at Auburn University has applied gas chromatography combined with infrared spectroscopy (GC-IR) to provide an alternative for analysis by forensic labs. In this webinar, Dr. Clark presented an overview of regioisomer differentiation using GC-IR and describe the advantages of the technique. He was joined by Mr. Lewis Smith of the New Jersey Police Department to describe his experience and advice in implementing GC-IR in a forensic lab. As synthetic compounds, new precursors, and isomers proliferate, it will become increasingly important for forensic laboratories to recognize the limitations of GCMS and have the ability to use GCIR when needed.

A certificate of completion is available for all who register and attend this webinar.


  • Randall Clark
  • Lewis Smith

Funding for this Forensic Technology Center of Excellence webinar has been provided by the National Institute of Justice, Office of Justice Programs, U.S. Department of Justice.

The opinions, findings, and conclusions or recommendations expressed in this webinar are those of the presenter(s) and do not necessarily reflect those of the U.S. Department of Justice.

Contact us at with any questions and subscribe to our newsletter for notifications.

Related Content

brain, DNA, bloodstain

Human Factors in Forensic Science Practice Sourcebook

Publication Forensic Science International: Synergy, March 2022 Editors Heidi Eldridge, PhD | RTI International Barbara A. Spellman, JD, PhD | University of Virginia School of Law Thomas Busey, PhD | Indiana University, Psychological and Brain Sciences Working Group Members Paul…
fire and cogwheels

Development of an Extraction Technique for Ignitable Liquid Residues (ILR) in the Field using Capillary Microextraction of Volatiles (CMV) and Person-Portable GC-MS

← Additional Portable Instrumentation for On-Scene Fire Debris Analysis Resources Date February 2022 Overview The work in this report is an extension of the capillary microextraction of volatiles (CMV) application (M. Torres et al., 2020) by Florida International University, reported…
fire, smoke, gas

Evaluation of Capillary Microextraction of Volatiles (CMV) Coupled to a Person-Portable Gas Chromatograph Mass Spectrometer (GC–MS) for the Analysis of Gasoline Residues

← Additional Portable Instrumentation for On-Scene Fire Debris Analysis Resources Publication Forensic Chemistry, March 2022 Authors Michelle N. Torres | Florida International University José R. Almirall | Florida International University Abstract A novel dynamic headspace extraction device, the capillary microextraction of…