Detection and quantification limits: origins and historical overview

Detection and quantification capabilities represent fundamental performance characteristics of measurement processes, yet there have been decades of c onfusion and miscommunication regarding the underlying concepts and termino logy. New, coordinated documents prepared for the International Union of Pu re and Applied Chemistry (IUPAC) [L.A. Currie, IUPAC Commission on Analytic al Nomenclature, Recommendations in Evaluation of Analytical Methods includ ing Detection and Quantification Capabilities, Pure Appl. Chem. 67 (1995) 1 699-1723] and the International Organization for Standardization (ISO) [P. Wilrich, Chairman, ISO/DIS 11843-1,2 (1995), Capability of Detection, ISO/T C69/SC6, ISO Standard, 11843-1, 1977] promise to alleviate this situation b y providing, for the first time, a harmonized position on standards and rec ommendations for adoption by the international scientific community. The te xt begins with (1) a brief historical summary of detection limits in chemis try, illustrating the critical need for the development of a sound and unif orm system of terms and symbols; and (2) a review of the ISO-IUPAC delibera tions and the ensuing harmonized position on concepts and nomenclature. In the following text a number of special topics are introduced, including: sp ecification of the measurement process, attention to the meaning and evalua tion of "sigma", special considerations for calibration (or regression)-bas ed detection and quantification limits, the central role of the blank, and finally, some challenges for the future. (C) 1999 Elsevier Science B.V. All rights reserved.