in chromatography
Asymmetry of a peak such that, relative to the baseline, the front is steeper than the rear. In paper chromatography and in thin-layer chromatography, the distortion of a zone showing a diffuse region behind the zone in the direction of travel.
Orange Book, p. 96
PAC, 1993, 65, 819 (Nomenclature for chromatography (IUPAC Recommendations 1993)) on page 837