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 algebr aic method that considers several contributions. Types of constant and vari able systematic errors are unambiguously identified on applying the model t o standard calibration, Youden calibration and standard additions method pe rformed in the presence of different matrix effects. Errors detection and c omposition calculation procedures emerge as mathematical consequences of th is simple treatment. Matrix effects of three types are distinguished, and a definition of interference is suggested. (C) 2000 Elsevier Science B.V. Al l rights reserved.