title: Quantifying selectivity: a statistical approach for chromatography.
abstract: A parameter for quantitative description of selectivity is defined. A model for quantification of selectivity based on a statistical approach is drawn up. Formulas for quantification of selectivity are derived, especially for chromatography. These are based on theoretical and-as far as needed-empirical functions (made evident by experimental data or numerical simulations) or at least worst-case assumptions. An example (GC-MS determination of atrazine in drinking water) shows how quantification of selectivity can be achieved in practice. The approach is intended to be used for validation purposes.