Trimethylation Enhancement using Diazomethane (TrEnDi) Enhances Mass Spectrometry-Based Analysis of Glufosinate and 3-(Methylphosphinico)propionic Acid in Complex Matrices

Glufosinate is the second most commonly used herbicide worldwide; it inhibits glutamine synthetase, which results in increased ammonia levels in plants and mammals. Due to their high polarity, low volatility, small size and lack of chromophores and fluorophores, glufosinate and its breakdown product 3-(methylphosphinico) propionic acid (3-MPPA) are difficult to detect at trace levels. Using the chemical derivatization strategy trimethylation enhancement using diazomethane (TrEnDi), glufosinate and 3-MPPA react with diazomethane and tetrafluoroboric acid to become permethylated, thus reducing their polarity and forming a fixed permanent positive charge on the amine group of glufosinate. When using reversed-phase high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS), analyte retention and sensitivity are increased after derivatization, 6.7-fold for glufosinate and 6.3-fold for 3-MPPA. TrEnDi methodology was applied to canola samples from two separate fields sprayed with Liberty®. Prior to derivatization, the analysis showed no signal associated with unmodified glufosinate or 3- MPPA; however, TrEnDi modification resulted in quantifiable signals for both permethylated species.

Name thesis:degree_name

Master of Science (M.Sc.)

Level thesis:degree_level

Master's

Discipline thesis:degree_discipline

Chemistry

Grantor dc:publisher

Carleton University

Year dc:date.issued

2023

Author dc:creator

• Sheedy, Krysten Lynn

Statement dc:rights

• Copyright © 2023 the author(s). Theses may be used for non-commercial research, educational, or related academic purposes only. Such uses include personal study, research, scholarship, and teaching. Theses may only be shared by linking to Carleton University Institutional Repository and no part may be used without proper attribution to the author. No part may be used for commercial purposes directly or indirectly via a for-profit platform; no adaptation or derivative works are permitted without consent from the copyright owner.

Language dc:language.iso

en

DOI

10.22215/etd/2023-15441

OAI identifier oai:identifier

oai:carleton.scholaris.ca:20.500.14718/42678