Analytical quality control

QC-based robust LOESS signal-drift correction

Use repeated biological QC injections to estimate and correct feature-specific signal drift along acquisition order.

Nature Protocols · 2011 · 10.1038/nprot.2011.335

LC-MSGC-MSUntargeted metabolomicsAnalytical quality control

What does this strategy enable?

QC-RLSC fits local curves to QC intensities and interpolates correction across study injections. It links experimental QC placement with computational drift estimation and subsequent quality assessment.

Transferable workflow

Workflow

  1. 1

    Interleave representative QC injections

    Retain injection order and batch labels with study and QC measurements.

  2. 2

    Prepare aligned feature intensities

    The documented LC-MS implementation uses XCMS for preprocessing.

  3. 3

    Fit QC correction curves

    Cross-validate feature-wise LOESS smoothing and interpolate across injections.

  4. 4

    Correct and assess reliability

    Normalize responses and inspect QC repeatability before combining batches.

Connected resources

Tools used in this strategy

Strategy profile

Components

Data acquisition, Preprocessing and feature extraction, Quality control, Statistical analysis

Scope and considerations

Designed for

  • Analytical drift correction when representative QC injections span the run.

Important requirements

  • Repeated QC observations with usable feature signals and recorded injection order.

Considerations

  • Sparse or unrepresentative QCs cannot reliably characterize every feature.
  • Check overfitting and corrected QC performance; correction does not fix experimental confounding.

Reusable resources

✓ Published method available

Publication

Dunn WB, Broadhurst D, Begley P, et al. Procedures for large-scale metabolic profiling of serum and plasma using gas chromatography and liquid chromatography coupled to mass spectrometry. Nature Protocols 6, 1060–1083 (2011).

doi:10.1038/nprot.2011.335