AssayIndex
Chromatography

Asymmetry factor (As)

Peak shape measure taken at 10 % of peak height: the width of the rear half divided by the width of the front half. Symmetric = 1.00. Above 1.50 the index marks integration unreliable.

Related terms

Rule AX-R12
Main-peak asymmetry above 1.50 at 10 % height. The trailing boundary is then drawn by judgement rather than by geometry, which makes the reported purity a range rather than a number. Asymmetry is a column finding: a re-injection on a fresh column usually clears it.

Where this term appears

The glossary exists to make record pages readable without a chemistry degree. Every technical term on a report resolves here.