Aerosol detection in plasma atomic emission spectrometry and condensation nucleation light scattering

This dissertation covers three areas of research involving aerosols. In the first part (Chapter II), the effects of aerosol-phase transport on discrete signals are reported. Discrete signals are transient in time and are associated with separation techniques and flow injection analysis. Liquid-phase transport of discrete signals is known to suffer from dispersion effects which increase detection limits and the required analysis time. If severe enough, dispersion in the liquid phase can even reduce the resolution present in a chromatographic separation. In this chapter, dispersion in the aerosol phase is investigated by considering the influence of residence time, transport volume and particle size on peak intensity, area and width. A comparison to liquid phase dispersion is also included.; In the second part of this research (Chapter III), the importance of aerosol particle size on response in inductively coupled plasma atomic emission spectrometry (ICP-AES) is investigated. In ICP-AES response is based on the formation of the excited-state elemental atomic and ionic species. Aerosols are routinely used as a method of introduction for liquid samples. As a result, it may be anticipated that aerosol particle size and residence time in the plasma will directly influence the formation of the desired excited state species. In this report, the emission intensity for various species as a function of particle size and height (residence time) in the plasma is presented.; The third area of research reported in this dissertation (Chapters IV and V) involves the development of an aerosol-phase light scattering detector for solution analysis based on the principle of condensation nucleation. In brief, the analyte (introduced in discrete form) is converted to an aerosol which is then dried. The dry particles are then mixed with the vapor molecules of butanol and rapidly cooled which causes the butanol vapor to condense onto the particles. The efficiency of the condensation step increases with particle size which increases with solute concentration. In these two chapters, the application of condensation nucleation to flow injection analysis and liquid chromatography is reported.