Calibration: A review for analytical chemists.

This paper presents a fairly complete revision of several aspects of the calibration procedure that are of practical interest to analytical chemists. After a discussion of least squares fitting, expressions are given for calculating calibration parameters and their confidence intervals, and for estimating the concentration of an unkown. The crucial question of model validation and interpretation is addressed, and then a numerical example, based on real spectrophotometric data, is solved in detail. Finally, practical advice on experimental design is given for three different analytical problems.