Use of proton transfer reaction time-of-flight mass spectrometry for quantitative monitoring of toxic nitramines in the environment

Tuesday, 16 December 2014
Liang Zhu1, Yngve Stenstrøm2, Armin Wisthaler1 and Claus Jørgen Nielsen1, (1)University of Oslo, Department of Chemistry, Oslo, Norway, (2)Norwegian University of Life Sciences, Ås, Norway
Naturally occurring aliphatic amines and industrially emitted aromatic amines and alkanolamines produce toxic nitramines, (R1R2)-N-NO2, when photo-oxidized in the atmosphere in the presence of nitrogen oxides (NOx). Particular concerns arise from amine-based CO2 capture where the amine solution may get nitrated by NOx in the flue gas. An on-line analytical technique for measuring nitramines in industrial emissions and in ambient air is thus in high demand.

Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) is a state-of-the-art technique for on-line measurements of volatile organic compounds (VOCs) in air. Herein, we report on the use of high mass resolution proton transfer reaction time-of-flight mass spectrometry (PTR-ToF-MS) for on-line analysis of nitramines. We generated a mass spectral library from a series of nitramines and investigated the analytical performance of PTR-ToF-MS in terms of sensitivity, precision, accuracy and detection limit. We will discuss limitations of the innovative technique and propose measurement strategies for future emission and ambient measurements.