Title

Method Development for Selective and Nontargeted Identification of Nitro Compounds in Diesel Particulate Matter

Source of Publication

Energy and Fuels

Abstract

© 2017 American Chemical Society. Nitro-aromatic compounds are associated with a host of adverse human health and ecological outcomes; however, current methods of detection are limited by the lack of accuracy for the nontargeted identification of nitro compounds. This paper describes the development of a novel, accurate, and selective method of identifying nitro compounds, especially nitro polycyclic aromatic hydrocarbons (PAHs), in complex soot mixtures. For the first time, high-performance liquid chromatography was used in combination with Orbitrap mass spectrometry for the nontargeted identification of nitro compounds. This method was validated on a mixture of 84 standard molecules containing 23 nitro compounds and then applied to a complex soot sample, the National Institute of Standards and Technology standard reference material (SRM) 1650a, to successfully identify 105 masses, 62% of which were monosubstituted nitro compounds. All nitro compounds reported in the latest certificate of analysis (COA) for SRM 1650b were successfully identified except for 1,3-dinitropyrene and 1,6-dinitropyrene. Compounds not reported in the COA of the SRM 1650b, including but not limited to 1,8-dinitropyrene, alkylated nitro-molecules of all masses in the COA of SRM 1650b, nitro-phenylnaphthalene isomers, dinitronaphthalene, nitro-phenols, nitro-keto-PAHs, nitro-carboxylic-PAHs, and other nitro partial polar compounds, were also tentatively identified. Future work will consider a larger set of classes, including isomers. This will help identify the chemical composition of mixtures in order to take proactive approaches to prevent health and environmental hazards.

Document Type

Article

First Page

11615

Last Page

11626

Publication Date

11-16-2017

DOI

10.1021/acs.energyfuels.7b01647

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