This project, supported in the Analytical and Surface Chemistry Program, is directed towards identifying those factors which limit the sensitivity and accuracy of atmospheric pressure plasma based mass spectrometry. During the tenure of this three-year standard grant, Professor Paul Farnsworth and his students at Brigham Young University will investigate the processes under which an ion beam is extracted from an inductively coupled plasma source, and directed into a mass spectrometer for analysis. Two techniques will be used to characterize this process. The first involves placing a nickel mesh in the path of the ion beam for a fixed time period prior to removal for analysis by scanning electron microscopy. The second approach is based on laser induced fluorescence of selected ionic species within the ion plume. These studies will allow a much more accurate picture of the ion beam extraction process, and should permit the design of highly efficient inductively coupled plasma mass spectrometers. Inductively coupled plasma mass spectrometry is rapidly becoming the method of choice for low level determinations of elemental composition for a wide range of samples in areas ranging from the environment to biotechnology. At present, the efficiency of ion transport in these devices is the limiting factor in their performance. Paul Farnsworth and his students at Brigham Young University are characterizing the ion extraction processes. The results from these studies could allow a new generation of spectrometers with improved accuracy and higher sensitivities to be designed.
