Hey everyone hope everyone is having a fantastic day!

So i'm pretty new to LC MS, I've done plenty of LC and a little of ICP-MS and GC-MS in my work history. When I performed the ICP/GC MS, all the methods were pretty much done for me so I never really had to figure out much about developing methods but at my new job I'll be in at the ground floor for running an LC-MS QTOF on oligonucleotides. My question is, when Im trying to determine molecular weight of the oligo, am I just picking the spectrum with the highest most abundance in the spectrum? I have never run this type of sample before nor have done it using QTOF. I don't know if I'm explaining this clear enough sorry!

regards,