Detection and identification of ethanal-derived spin-trapped free radicals using headspace thermal desorption gas chromatography-mass spectrometry (TD-GC-MS)

Manzoor, K; Mishra, S; Podmore, ID

Abstract

In this study, we demonstrate a novel approach to the detection and identification of the
products of spin-trapped free radicals. Hydroxyl free radicals were generated by Fenton-based
chemistry in the presence of ethanal and the spin-trapping agent
N-tert-butyl-
-phenylnitrone
(PBN). The resulting volatile compounds present in the reaction vial headspace were collected
using thermal desorption (TD) and analysed by gas chromatography-mass spectrometry (GCMS). Eleven compounds were detected in the headspace, and their identification was aided by
using either a fluorinated or deuterated analogue of PBN as an alternative spin trap and/or
deuterated ethanal (CD
3CHO) as the secondary source of free radicals. The electron-ionisation
(EI) mass spectra clearly demonstrate the “capture” of methyl radicals; two of the compounds
detected were identified as containing one methyl group derived from ethanal, and four were
shown to contain two methyl groups. This study demonstrates that sampling the reaction
headspace using TD-GC-MS is a viable method for analysing products of free radical trapping,
and potentially may be applied to a wide range of free radical systems.

Citation

Manzoor, K., Mishra, S., & Podmore, I. (2020). Detection and identification of ethanal-derived spin-trapped free radicals using headspace thermal desorption gas chromatography-mass spectrometry (TD-GC-MS). Free Radical Research, 54(10), 745-755. https://doi.org/10.1080/10715762.2020.1841183

• Journal Article Type: Article
• Acceptance Date: Oct 19, 2020
• Online Publication Date: Oct 22, 2020
• Publication Date: Nov 9, 2020
• Deposit Date: Oct 23, 2020
• Publicly Available Date: Oct 22, 2021
• Journal: Free Radical Research
• Print ISSN: 1071-5762
• Electronic ISSN: 1029-2470
• Publisher: Taylor and Francis
• Volume: 54
• Issue: 10
• Pages: 745-755
• DOI: https://doi.org/10.1080/10715762.2020.1841183
• Publisher URL: https://doi.org/10.1080/10715762.2020.1841183
• Related Public URLs: http://informahealthcare.com/journal/fra/
• Additional Information: Access Information : This is an Accepted Manuscript of an article published by Taylor & Francis in Free Radical Research on 22nd October 2020, available online: http://www.tandfonline.com/10.1080/10715762.2020.1841183.