has_metric_category has_units has_value_concept has value type n-tuple ID based metric single run based metric retention time metric MS2 metric identified MS2 quantile RT fraction RT-MSMS-Q4 MS:4000188 The metric informs about the dynamic range of the MS2 identification process along the chromatographic separation. For MS2 scans, the comparability of the values depends on the acquisition mode and settings to select ions for fragmentation. RT-MSMS-Q1 MS RT-MSMS-Q3 RT-MSMS-Q2 The interval used for acquisition of quantiles of all identified MS2 events, after user-defined acceptance criteria are applied, divided by retention time duration. The number of values in the tuple implies the quantile mode. In case of multiple acceptance criteria (FDR) available in proteomics, PSM-level FDR should be used for better comparability. fraction