Dear IFEFFIT members, I am sorry to bother you again. I asked about S02 selection for the first major revision. I just received the second revision. The reviewer is not satisfied with one S02 value for all our samples. " 1. I am still not satisfied with selected SO2 value (it is set to 0.85). SO2 is not transferable between different samples and detection methods. It is not possible to use a value obtained from different compound using transmission measurement mode to completely different other compound measured using fluorescence mode. One method to fix SO2 value is to measure diluted solution (to avoid self-absorption) of reference material in fluorescence mode. Other is to use multiple spectra fitting for all samples of interest (e.g. with Sb(V)) measured using fluorescence mode where SO2 parameter is the same for all samples. At the same time I am confident that CN values 5.6, 7.1 and 6.9 correspond to CN(Sb-O)=6. I suggest reconsidering the SO2 value for measurements in fluorescence mode. " We do get the S02 from a similar reference material measured in transmission mode, and our samples were all measured in fluorescence mode. It is not possible to measure the diluted reference material in fluorescence mode in one or two months. If you could give me some suggestions, that would be great. -- Best Regards, Peng Liu