 Pooled quality-control sample

A pooled quality-control sample combines representative portions of study samples and is measured repeatedly to monitor analytical consistency. In metabolomics, it provides a shared mixture against which changes in retention, signal intensity, or instrument drift can be tracked.

It is distinct from a biological replicate and from a certified concentration standard. A stable pooled sample supports assessment of measurement reproducibility, but does not by itself prove correct identification or absolute quantification of every metabolite.