Shoulder
An unresolved peak appearing as an asymmetric bulge on the leading or trailing edge of a larger peak. The main source of integration ambiguity, and the reason the index asks for the integration convention rather than setting a resolution threshold.
Related terms
- Resolution (R)
- Separation between two peaks: R = 2(t₂ − t₁)/(w₁ + w₂). R = 1.5 is baseline resolution. The index computes and reports R to the nearest named impurity on every record that has one, and applies no acceptance criterion to it — resolution to whichever impurity happens to elute closest is a property of the compound and the gradient, not a system-suitability requirement.
- Drop-line integration
- Separating two overlapping peaks with a vertical line dropped from the valley between them. Unbiased when the peaks are of comparable size.
see also Asymmetry factor (As) · Valley
see also Valley-to-valley integration · Tangent skim
Where this term appears
The glossary exists to make record pages readable without a chemistry degree. Every technical term on a report resolves here.
- Assay report records — the term appears in result tables, peak tables and provenance blocks
- Method references — where the measurement behind the term is defined
- All 21 glossary terms beginning with S