Multiple-reaction monitoring channels

Despite the enormous selectivity provided by multiple-reaction monitoring through targeting individual precursor and product ion mass combinations, interference from cross talk can still confound mixture analysis in LC/MS. Cross talk is defined as contributions from ions of similar or identical mass to other precursor-product ion channels. Cross talk can occur via two distinct pathways. Chemical interference due to in-source fragmentation of metabolites or related substances will yield ions identical to the analyte precursor which pass through the first quadrupole. This type of interference can only be detected if the metabolite is chromatographically resolved from the analyte peak. 

Note SRM is preferably performed on triple quadrupole, quadrupole ion trap, and Q-TOF hybrid instruments due to their ease of setting up the experiment and to their speed of switching between channels if monitoring of multiple reactions plays a role. 

---