Width of the back of a peak (\(b\)) divided by the width of the front (\(f\)) of the peak measured at \(\pu{10\%}\) of the peak height. See figure in asymmetry factor.
Source: PAC, 2017, 90, 181. 'Terminology of separation methods (IUPAC Recommendations 2017)' on page 196 (https://doi.org/10.1515/pac-2017-0111)