title: Total indices as a tool to estimate sum content of similar analytes.
abstract: The estimation of sum content of similar analytes without their separation often requires the use of total indices (TIs) expressed in terms of the standard substance concentration. Theoretic and metrological features of such indices are discussed in the review. The sum content of similar analytes is estimated by any TI with a certain systematic error. It can be minimized by selecting a standard substance and/or with the justification of sensitivity coefficients for individual analytes. The publications are pointed out in which new TIs are offered or new methods to measure known TIs are described. The corresponding studies are predominantly associated with two kinds of estimates: (a) total content of organic substances in waters and (b) the total antioxidant activity of foodstuffs.
authors.affiliation: Department of Analytical Chemistry, Omsk State University, Omsk 644077, Russia.
authors.forename: Viacheslav I
authors.initials: VI
authors.lastname: Vershinin
keywords: Chemical analysis; Determination of organic substances; Environmental analysis; Standard substance; Sum content of similar analytes; Total indices; Uncertainty of results