Contributions of organic nitrogen to the gas phase and speciation of amines in ambient samples

Katherine Benedict1, Amy P. Sullivan2 and Jeffrey L. Collett, Jr.3

Atmospheric reactive nitrogen is a mixture of inorganic compounds like NOx, nitric acid, ammonia, nitrate, and ammonia and organic compounds that contain nitrogen. There is significant uncertainty in the contribution of organic nitrogen compounds to the atmospheric reactive nitrogen budget and the deposition budget. Amines are a class of compounds known to be present in both the gas and aerosol phase but measurements of their abundance and speciation are limited. We have developed an ion chromatography method using a Dionex CS19 column with conductivity detection which can speciate more than 10 different amine compounds including the methyl and ethyl amines. A number of amine compounds were detected in variety of ambient filter and denuder samples analyzed and these results will be presented. The sampling efficiency of several amine compounds will be determined. Additionally, recent papers by Matsumoto and Yamato describe a method to determine the basic and acidic organic nitrogen contribution using a denuder sampling technique. In this work, we test this method in the laboratory and with samples collected in Rocky Mountain National Park. Results of laboratory testing examine carryover between the sodium carbonate denuder used for nitric acid determination and “acidic organic nitrogen” and the phosphorous acid coated denuder used for ammonia determination and “basic organic nitrogen”. The contribution of “basic organic nitrogen” and “acidic organic nitrogen” will be presented for select periods of sampling in Rocky Mountain National Park.


1Colorado State University,
2Colorado State University,
3Colorado State University,