All- I am curious as to the number (if any) of folks who have tried to do laser ablation with BrF5 for oxygen isotope analysis of sulfate minerals as well as hydroxylated sulfur/sulfate species. I would like to analyze alunite, and would like to hear from anyone who has gone down this road. Also, I am pondering the wisdom of doing clay minerals by laser with BrF5, and recall several conversations with others who were attempting this. We have an airlock design similar to John Valley's/Mike Spicuzza's in Madison, but I would like to know if the spattering issues during heating have been solved. Dr. Doug Crowe Department of Geology University of Georgia Athens, GA 30602 USA [log in to unmask]