Systematic errors: detection and correction by means of standard calibration, Youden calibration and standard additions method in conjunction with a method response model

Responses of analytical methods are interpreted by means of a simple algebraic method that considers several contributions. Types of constant and variable systematic errors are unambiguously identified on applying the model to standard calibration, Youden calibration and standard additions method performed in the presence of different matrix effects. Errors detection and composition calculation procedures emerge as mathematical consequences of this simple treatment. Matrix effects of three types are distinguished, and a definition of interference is suggested. (C) 2000 Elsevier Science B.V. All rights reserved.