Dear Ifeffit Community, I am currently working on project "Evaluating Speciation of Thallium in Coal Fly Ash". The project was accepted by APS and we will conduct our measurement on beamline 5-BM-D. My fly ash sample has Tl concentration ranging from 0.5ppm to 13ppm. How can I know whether the sample can generate enough photon counts if using fluorescence mode? what would be the appropriate sample preparation procedure I should follow? Is there any interference I should pay attention to? I understand that I should use Hephaestus, but I don't know how to do that if my sample contains lots of different oxides. I attached the elemental composition in this email. Most metals should be in form of oxides, or sulfates. Any input would be highly appreciated, Mengling -- Mengling Yi Stuckman Graduate Research Assistant Civil and Environmental Engineering and Geodetic Science Ohio State University 2070 Neil Ave., Columbus, OH, 43210