The U.S. Bureau of Mines (USBM) and Weber State University (WSU) have developed an on-line analysis system for copper electrolytic solutions in a laboratory-scale decopperization electrolytic cell using a portable energy-dispersive X-ray fluorescence (XRF) unit. The portable XRF unit utilizes Fe-55 and Cm-244 radioactive isotope sources for sample analysis. Copper, sulfur, and arsenic were successfully analyzed directly in electrolytic purification solutions without any dilution or sample alteration. Interelement deconvolution was conducted to compensate for interferences resulting from matrix absorption of copper fluorescence by sulfur. The ubiquitous presence of sulfur in copper refining operations necessitates sulfur correction in the analysis of copper by XRF. A unique flow-through sampling cell was engineered and constructed for the portable XRF unit which allowed real-time analysis of a continuously pumped sample stream from the electrolytic cell.
Robert A. Davidson, Edward B. Walker, Craig R. Barrow, and Charles F. Davidson, "On-Line Radioisotope XRF Analysis of Copper, Arsenic, and Sulfur in Copper Electrolyte Purification Solutions," Appl. Spectrosc. 48, 796-800 (1994)