Detection and quantification limits: origins and historical overview

Abstract

Detection and quantification capabilities represent fundamental performance characteristics of measurement processes, yet there have been decades of confusion and miscommunication regarding the underlying concepts and terminology. New, coordinated documents prepared for the International Union of Pure and Applied Chemistry (IUPAC) [L.A. Currie, IUPAC Commission on Analytical Nomenclature, Recommendations in Evaluation of Analytical Methods including Detection and Quantification Capabilities, Pure Appl. Chem. 67 (1995) 1699–1723] and the International Organization for Standardization (ISO) [P. Wilrich, Chairman, ISO/DIS 11843-1,2 (1995), Capability of Detection, ISO/TC69/SC6, ISO Standard, 11843-1, 1977] promise to alleviate this situation by providing, for the first time, a harmonized position on standards and recommendations for adoption by the international scientific community. The text begins with (1) a brief historical summary of detection limits in chemistry, illustrating the critical need for the development of a sound and uniform system of terms and symbols; and (2) a review of the ISO–IUPAC deliberations and the ensuing harmonized position on concepts and nomenclature. In the following text a number of special topics are introduced, including: specification of the measurement process, attention to the meaning and evaluation of “sigma”, special considerations for calibration (or regression)-based detection and quantification limits, the central role of the blank, and finally, some challenges for the future.