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Phosphine detection in veterinary samples using headspace gas chromatography/tandem mass spectrometry with multiple reaction monitoring
Author(s) -
Lehner Andreas F.,
Johnson Margaret,
Buchweitz John P.
Publication year - 2020
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.8738
Subject(s) - chemistry , phosphine , chromatography , gas chromatography , repeatability , mass spectrometry , detection limit , tandem mass spectrometry , gas chromatography–mass spectrometry , gas chromatography/tandem mass spectrometry , selected reaction monitoring , analytical chemistry (journal) , organic chemistry , catalysis
Rationale Determination of phosphine exposure from zinc or aluminum phosphide fumigants continues to be a routine analytical requirement in veterinary forensic toxicology. There is a need for a more reliable and specific method than simple gas chromatography/mass spectrometry (GC/MS) analysis of sample solvent extracts, as GC/MS of extracts on capillary columns used for general screens involves significant interference from air peaks. Methods GC/MS/MS headspace analysis of acid‐generated phosphine gas enabled study of the feasibility of devising multiple reaction monitoring (MRM) approaches to the determination of phosphine with greater specificity. Results Collision‐induced dissociation in GC/MS/MS showed that phosphine generated m / z 34 → 31, 32 and 33 ion transitions by sequential proton release as well as minor transitions m / z 34 → 47, 34 → 63 and 63 → 31.5 by intermolecular collisions and double charging. Study of the formation of these product ions enabled development of MRM settings for a highly useful headspace method for phosphine detection. Conclusions The method was validated over a working range of 5–100 ppm of phosphide generating phosphine gas which enabled retention of regular screen capillary columns without necessitating separation from air components. The method should have adequate sensitivity and reliability for veterinary toxicology laboratories confronting specimens from animals poisoned by crop fumigants.