has_column has_metric_category external reference identifier table ID based metric single run based metric retention time metric targeted compound name targeted compound retention time deviation targeted compound retention time deviations In contrast to the aggregated MS:4000241, this metric retains the per-compound values, which makes it possible to see whether a retention time shift affects all compounds alike (e.g., due to a delayed injection) or only part of the retention time range (e.g., due to a changed oven temperature program). MS MS:4000245 The deviation of the observed from the expected retention time (observed minus expected) for each compound of a set of targeted/expected compounds (e.g., from a QC mix). The compounds are identified by the 'targeted compound name' and 'external reference identifier' columns, and the corresponding deviations are given in the 'targeted compound retention time deviation' column. Compounds missing from the table are interpreted as not detected. The compounds need to be confidently identified, ideally by several characteristics (e.g., mass spectrum and retention time).