I just ran into (for me) a new problem. Iolite is sporadically spitting out negative LODs values for a few of my analytes (Na, Mn, Fe, and Ni) in a study of SiC. I am familiar with the Longerich method generating "infinitely low" LODs when there is no variation in the background, but negative values are a new one. All LOD calculation options in Iolite are doing the same thing for those ablations where this problem crops up. Any ideas? Thanks!