University of North Florida
Browse the Citations

Contact Info

Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Website: @unf

View Stuart Chalk's profile on LinkedIn


Classification: Gas -> aerosol

Citations 1

"Determination Of Ammonium In Aerosols, Cloud And Rain Water, And Of Gaseous Ammonia In The Troposphere"
Fresenius J. Anal. Chem. 1987 Volume 327, Issue 1 Pages 16-16
U. Sprenger and K. Bächmann

Abstract: Four methods were compared for the determination of NH4+. An UV - visible spectrophotometric determination is described which involved treatment of NH4+ with an alkaline solution of 4,4'-bis-(3-methyl-1-phenylpyrazolin-5-one) in the presence of chloramine T at pH 6, extraction with trichloroethylene after acidification, and measurement of the absorbance at 455 nm. Two flow injection analysis methods are described involving injection of a sample into a stream of NaOH to produce NH3 which diffuses across a permeable membrane into a flowing acceptor stream. In the first method, the acceptor is bromothymol blue solution and the absorbance is measured at 620 nm, and in the second, the acceptor is water and the change in conductivity is measured. The last method described involves ion chromatography and conductivity detection. The sample volume, detection limits, reproducibilities and analysis times are given for the four methods. A possibility for sampling gaseous NH3 is by formation of ammonium oxalate on cellulose filters coated with oxalic acid.
Ammonium Spectrophotometry Cellulose Gas diffusion Membrane Method comparison