The design and application of a newly-developed Siemens multichannel wavelength x-ray fluorescence spectrometer that has been specially adapted to the needs of the Environmental Protection Agency for rapid analysis of particulate samples is described. The system consists of sixteen fixed-wavelength spectrometers which are optimized for sixteen pre-selected elements and a computer-operated scanning channel which is used to determine additional elements that might be desired on a given sample. A minicomputer operates the instrument and custom-designed sample changer and processes the data.
Requirements for standards suitable for air pollution samples and the approaches used for the preparation of thin layer standards are discussed. Sensitivities, detection limits for elements of interest in air pollution, and the relative merits of aerosol filter types for x-ray fluorescence analysis have been determined. The system has been used to measure the elemental composition of a large number of samples from stationary source emissions, mobile sources, and ambient air.