Synthetic opioids such as fentanyl account for over 71,000 of the approximately 107,000 overdose deaths reported in the United States in 2021. Fentanyl remains the fourth most identified drug by state and local forensic laboratories, and the second most identified drug by federal laboratories. The unambiguous identification of fentanyl‐related substances (FRS) is challenging due to the absence or low abundance of a molecular ion in a typical gas chromatography‐mass spectrometry (GC‐MS) analysis and due to a low number of fragment ions that are similar among the many potential isomers of FRS. This study describes the utility of a previously reported gas chromatography‐infrared (GC‐IR) library for the identification of FRS within a blind, interlaboratory study (ILS) involving seven forensic laboratories. Twenty FRS reference materials, including those with isomer pairs in the library, were selected based on either their presence in the NIST library and/or some similarity of the mass spectra information produced. The ILS participants were requested to use the Florida International University (FIU) GC‐MS and GC‐IR libraries supplied by FIU to search for matches to their unknown spectra generated from in‐house GC‐MS and GC‐IR analysis. The laboratories reported improvement in the positive identification of unknown FRS from ~75% using GC‐MS alone to 100% correct identification using GC‐IR analysis. One laboratory participant used solid phase IR analysis, which produced spectra incompatible with the vapor phase GC‐IR library to generate a good comparison spectrum. However, this improved when searched against a solid phase IR library.
- Award ID(s):
- 1505197
- NSF-PAR ID:
- 10051442
- Date Published:
- Journal Name:
- Journal of Separation Science
- Volume:
- 39
- Issue:
- 2
- ISSN:
- 1615-9306
- Page Range / eLocation ID:
- 358 to 366
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract Rationale Contaminants present in ambient air or in sampling lines can interfere with the target analysis through overlapping peaks or causing a high background. This study presents a positive outcome from the unexpected presence of
N ‐methyl‐2‐pyrrolidone, released from a PALL HEPA filter, in the analysis of atmospherically relevant gas‐phase amines using chemical ionization mass spectrometry.Methods Gas‐phase measurements were performed using a triple quadrupole mass spectrometer equipped with a modified atmospheric pressure gas chromatography (APGC) source which allows sampling of the headspace above pure amine standards. Gas‐phase
N ‐methyl‐2‐pyrrolidone (NMP) emitted from a PALL HEPA filter located in the inlet stream served as the ionizing agent.Results This study demonstrates that some alkylamines efficiently form a [NMP + amine+H]+cluster with NMP upon chemical ionization at atmospheric pressure. The extent of cluster formation depends largely on the proton affinity of the amine compared with that of NMP. Aromatic amines (aniline, pyridine) and diamines (putrescine) were shown not to form cluster ions with NMP.
Conclusions The use of NMP as an ionizing agent with stand‐alone APGC provided high sensitivity for ammonia and the smaller amines. The main advantages, in addition to sensitivity, are direct sampling into the APGC source and avoiding uptake on sampling lines which can be a significant problem with ammonia and amines.
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1002/jssc.201500771
