• ANALYTICAL DEVELOPMENTS IN X-RAY EMISSION SPECTROMETRY.

      Fernando, Quintus; PERRON, STEVEN JOSEPH. (The University of Arizona., 1982)
      X-Ray emission techniques have been developed for the analysis of unusual and difficult samples that cannot be analyzed by conventional analytical techniques. Three X-ray techniques have been investigated, including radioisotope-induced X-ray fluorescence (RXRF), proton-induced X-ray emission (PIXE) and high resolution PIXE. Low flux radioisotope X-ray sources have been used to non-destructively characterize the elements present in photographic papers and emulsions. The information obtained has proven valuable for cataloging and preserving photographic prints of historical significance. Radioisotope X-ray sources have also been used in the development of low-cost, portable instrumentation useful for quantitating a variety of toxicological samples, including urine and feces samples to determine the elimination rates of X-ray contrast media containing dysprosium. The PIXE technique has been applied to the analysis of forensic samples, including bullet lead, tissue fragments and thin metal coatings, and has been compared with other non-destructive methods of analysis. Sample preparation techniques and analytical procedures have been developed for general, thin target, quantitative PIXE analysis. These procedures were applied to the analysis of five NBS standard reference materials, and to the analysis of deep-sea ferromanganese nodules. A high resolution (2 eV) PIXE system has been developed to aid in the deconvolution of overlapping X-ray peaks encountered in conventional PIXE spectra. This system has been applied to the measurement of chemical shifts in the X-ray emisson spectra of transition metal compounds.