Collection by Impregnated Cartridge Method-Determination of Ammonia and Ammonium Salts in Atmosphere by Ion Chromatography
1989 Volume 24 Issue 3 Pages 227-233
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1989 Volume 24 Issue 3 Pages 227-233
An application of ion chromatography (IC method) to the determination of concentration of ammonia (NH3) and ammonium salts (NH4+) in the atmosphere using filter and Sep-pak C18 cartridge impregnated with mixed solution of 5% phosphoric acid (H3PO4) and 5% glycerin was examined.
It was found that the collection efficiency of NH3 in the atmosphere was good by the use of impregnated cartridge at flow rate of 1-10l/min. And concerning to the aspect of determination of concentration of ammonium ion with IC method, this method was superior in respect of simplicity, rapidity and detection limit to the conventional method such as indophenol method. However, there are a few defect as follows: the calibration curve was non-lineality when the concentration of ammonium ion in the solution was over 1 pg/ml. Also the concentration of H3PO4 of sample solution should be treated to below 0.1%, as the H3PO4 used to collect NH3 interfered with the determination of ammonium ion.
The method established in this study was applied to the analysis of NH3 and NH4+ collected in Nara City in a period from May, 1987 to Apr., 1988. The annual mean concentration of NH3 and NH4+turned out to be as follow: 11.17 ppb for NH3 and 2.03μg/m3 for NH4+. The concentration of NH3 was high in summer season and low in w inter season, while the concentration of NH4+ was a little variation through a year. And the concentration of NH3 exhibited about 1.5 to 8 times to the concentration of NH4+ and the NH3/NH4+ ratios were recognized dependency on the temperature.
