Are there any opinions/experience out there on the utility of LC-TOF or LC-QTOF analysis of biological extracts for the identification of major metabolites? Has anyone yet done a head-to-head comparison with radiolabel dosing to see if you get comparable answers? I do have the 2006 Zhu paper, and a couple of others. I am wondering if having a Q-TOF means you can forego the joys of doing a radioactive animal study...