Hello everyone, Sorry for bothering you again. I am using least-squares peak fit and linear combination fit to analyze my samples. I have spent tons of time on it, and it really makes me crazy. Why can't I get consistent results from these two methods? Please see the attached file. Both of these methods work well individually, but linear combination fit always need more peaks than peak fit to get an 'ok' fitting. Should I stick on one method for all my samples, no matter what results the other one gives? It is confusing me so much. Could anyone help me out? Thank you in advance for your help! Jenny __________________________________________________________________ Instant Messaging, free SMS, sharing photos and more... Try the new Yahoo! Canada Messenger at http://ca.beta.messenger.yahoo.com/