Organic nitrogen has been studied sparsely in wet deposition measurements and to better understand the sources and importance of organic nitrogen in deposition, we need to understand the forms of organic nitrogen in ambient atmosphere.   In Northeastern Colorado agriculture is an importance source of atmospheric nitrogen compounds, specifically and most commonly studied is ammonia.  However, amines are also emitted from a variety of agricultural activities but few studies have focused on these organic nitrogen compounds and the processes that these compounds will undergo to form particulate matter.  

A set of samples from the spring of 2019 (April) were collected using URG denuder/filter-pack sampling in the following Colorado locations: Greeley, Fort Collins, and in Rocky Mountain National Park (RMNP).  These samples were analyzed for a suite of amine compounds, inorganic ions, and total

nitrogen (TN).    Additionally a Micro-Orfice Uniform Impactor Depositor (MOUDI) was operated at the Fort Collins site to collect highly resolved size distribution data was collected for the summer and winter seasons.   The MOUDI samples were analyzed for inorganic ions, amines, and organic acids to assess the processes that were forming amine particulate. While 16 different amines were analyzed, there were several that were observed below the detection limit. The amines that were observed in higher concentrations included methylamine, dimethylamine, trimethylamine, tert-butylamine, sec-butylamine, iso-butylamine, and amylamine.

In this study we will examine the contribution of amines to total organic nitrogen and the inorganic nitrogen species measured.  We will also investigate the size distribution of the various measured species to better understand aerosol formation processes in the region. Amines were generally greatest in concentration at the Greeley site and smallest in concentration at the RMNP site, as we expected due to proximity of sources.  Overall, the combined analysis of spatial and size resolved data gives a first insight into the quantification of amines for this area.