The use of experimental design in separation science

In this tutorial, the application of experimental designs in separation science is discussed. Method optimization is often divided into screening and optimization phases. In the screening step, many factors, potentially affecting the separation, are screened to identify those with the largest effects. These are then further examined in an optimization phase, to determine the best separation conditions. After optimizing the method, it should be validated, before use for quantitative purposes. Robustness testing is part of method validation and examines the effects on the responses of small changes in method conditions. During the first phase of method optimization and during robustness testing, so-called screening designs are usually applied, whereas during the second phase of optimization, response-surface designs are often used. In this tutorial, the different steps in the application of both types of design are explained and elaborated with some examples.