Analysis of organic nitrogen compounds in urban aerosol samples using GCxGC-TOF/MS

Despite the fact that a significant number of organic and inorganic compounds have been measured in aerosol samples, relatively little is known about the organic nitrogen (ON) content. The ON components of 23 urban aerosol samples were characterized using a direct thermal desorption technique (DTD) together with comprehensive two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC-TOF/MS). Between 17 and 57 various ON compounds mainly nitriles, amides, amines, and nitro compounds were found in individual samples collected on different dates from the same location. In total identifications were made for over 100 ON different compounds in urban aerosol. Aminomethanesulfonic acid, o-cyanobenzoic acid and hexadecanenitrile were found in all samples. 4-[2-(methylamino)ethyl]- phenol, pyridine, 4,4a,5,7a-tetrahydro-8,8-dimethyl-(1a,4a,4aa,7aa)-1,4-methano-1H-cyclopenta[d] pyridazine, caprolactam, tetradecanitrile, penoxaline, tetradecanamide, and eicosanenitrile were detected in many of the samples. ON compounds contained 1-4 N atoms and ranged in MW from 59-302 Da. DTD proved an efficient tool for the analysis of volatile organic nitrogen components in ambient aerosol, avoiding more costly and time consuming off-line extraction techniques. Desorption of ON standards on filter papers showed efficient transfer to the GC.