High-Sensitivity Analysis of Ammonia, Methylamine, and Trimethylamine in Environmental and Energy Fields

Introduction

Nitrogencompounds such as ammonia and various amines are known as malodorous substances, and besides concern associated with the offensive odors, they have potential adverse affects on human life. On the other hand, ammonia's high energy density per unit volume and the ease with which it can be stored and transported has resulted in increased research in its use as a medium for the storage of hydrogen in fuel cells. The increased use of ammonia and the close proximity of associated amines to humans accentuate the necessity for methods of accurate and rapid detection and quantitation of these substances. The flame thermionic detector (FTD) is known as a high-sensitivity detector for nitrogen compounds, but because the FTD does not respond to ammonia, it cannot be used for its detection. Typically, ammonia analysis by gas chromatography (GC) is conducted using a thermal conductivity detector (TCD), but measurement is difficult using TCD unless the concentration is greater than about 100 ppm. The dielectric barrier discharge ionization detector (BID) permits detection of nearly all compounds, except for helium and neon, at higher sensitivity than that possible with TCD and FID detectors. Here, we introduce examples of analysis at the ppm level of ammonia and methylamine in water, and of trimethylamine in water by GC-BID.

September 25, 2014 GMT