I was wondering if someone could please help me with my lab. We are synthesizing NMR shift reagents in order to determine what isomers are present in a mixture of xylenes. I have the NMR and I can't figure out how to determine which isomers are present. If I have the NMR of o,m,p-xylene by themselves I can tell the difference between each one, but I can't figure out how to determine which of the isomers are present in an unknown mixture of them. How can I use the NMR to determine which isomers are present? What should I be looking for?