A term which expresses qualitatively the extent to which other substances interfere with the determination of a substance according to a given procedure.
PAC, 1983, 55, 553
(Recommendations for the usage of selective, selectivity and related terms in analytical chemistry)
on page 555
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook