Mass chromatogram

The total ion current chromatogram (TICC) represents the summed intensity across the entire range of masses being detected at every point in the analysis.

In complex samples, the TICC often provides limited information as multiple analytes elute simultaneously, obscuring individual species.

This is useful for re-examining data to detect previously-unsuspected analytes, to highlight potential isomers, resolve suspected co-eluting substances, or to provide clean chromatograms of compounds of interest.

This differs significantly from the extracted-ion chromatogram mentioned above in that only data for the ion(s) of interest are collected in a SIM experiment; for extracted-ion chromatograms (EIC or XIC), data for an entire mass range are collected during the run and then examined for analytes of interest after the completion of the run.

The technology progress in the MS/MS area lead to the development of MRM, Multiple Reaction Monitoring, which allows simultaneous detection of several coeluting analytes with different parent and/or product ions.