The portion of a differential chromatogram recording the detector response when a single component is eluted from the column. If separation is incomplete, two or more components may be eluted as one unresolved peak.
Sources:
Orange Book, 2nd ed., p. 96 (https://media.iupac.org/publications/analytical_compendium/)
PAC, 1993, 65, 819. 'Nomenclature for chromatography (IUPAC Recommendations 1993)' on page 835 (https://doi.org/10.1351/pac199365040819)