Air quality and the selective detection of ammonia in the presence of carbon monoxide, toluene, benzene, and xylene

Abstract

Air quality is an important factor especially in areas where humans are exposed to animal excrement. The selective detection of NH3, especially in the presence of CO provides an important means of protecting the health of workers in the dairy, swine, and poultry industries especially in enclosed barn areas. In addition, selective non-invasive detection of NH3 can play an important role in breath analysis especially for asthmatics. We assess the sensitivity of a variety of untreated and decorated porous silicon (PS) interfaces to NH3 at room temperature in the presence of carbon monoxide, toluene, benzene, and xylene. Interfaces, selective ranging from 102 105 for NH3, are demonstrated. The reversible interaction of NH3 with a PS interface completely overwhelms that for CO. A SnOx-decorated PS interface is used to evaluate the NH3-toluene system as the much weaker toluene signal corresponds to that of a weak base. SnOx and AuxO(x> > 1) decorated and PS interfaces are used to evaluate the NH3-benzene system as a much weaker benzene signal corresponds to that of a weak acid. A SnOx decorated PS interface is used to evaluate the NH3-xylene system as a much weaker xylene signal corresponds to that of a weak base.