Enhanced Recognition of Spin Trapped Radicals In Complex Mixtures: Deuterated Nitronyl Adducts Provide A Gas Chromatographic/Mass Spectrometric Marker

Abstract

The use of deuterated analogues of α-phenyl-N-tert-butyl nitrone (PBN) are reported for GC/MS analysis of spin trapping products. PBN-d₉ and PBN-d₄₁, deuterated in the tert-butyl group (the latter also deuterated in the phenyl ring), result in a more diagnostic fragment ion, C₄D₉ ⁺ (m/z = 66) which improves the recognition of PBN adducts in mixtures. This feature has helped identify a new 1,3-radical addition product of PBN-d₉ formed during azobis(isobutyronitrile) thermolysis (addition of 2-cyano-2-propyloxyl followed by 2-cyano-2-propyl radicals). the ¹³C-trichloromethyl radical adduct of PBN-d₁₄ produced during ¹³C-carbon tetrachloride incubation with rat liver micrcsomes was identified by GC/MS in a complicated biological extract mixture.

Key Words:

• Spin Trapping
• Gas Chromatography/Mass Spectrometry
• Deuterium Substitution
• α-Phenyl-N-tert-Butyl Nitrone (PBN)
• Nitroxides
• Aminoxyls
• Alkoxylamines