has_metric_category has_units has value type n-tuple ID free metric single run based metric retention time metric chromatogram metric obsolete TIC quarters RT fraction true The metric informs about the dynamic range of the acquisition along the chromatographic separation. The metric provides information on the sample (compound) flow along the chromatographic run, potentially revealing poor chromatographic performance, such as the absence of a signal for a significant portion of the run. MS:4000054 MS MS:4000183 RT-TIC-Q1 RT-TIC-Q4 RT-TIC-Q3 RT-TIC-Q2 OBSOLETE. The interval when the respective quarter of the TIC accumulates divided by retention time duration. fraction