Is it really necessary to validate an analytical method or not? That is the question

Abstract

Method validation is an important requirement in the practice of chemical analysis. However, awareness of its importance, why it should be done and when, and exactly what needs to be done, seems to be poor amongst analytical chemists. Much advice related to method validation already exists in the literature, especially related to particular methods, but more often than not is underused. Some analysts see method validation as something that can only be done by collaborating with other laboratories and therefore do not go about it. In addition, analysts’ understanding of method validation is inhibited by the fact that many of the technical terms used in the processes for evaluating methods vary in different sectors of analytical measurement, both in terms of their meaning and the way they are determined. Validation applies to a defined protocol, for the determination of a specified analyte and range of concentrations in a particular type of test material, used for a specified purpose. In general, validation should check that the method performs adequately for the purpose throughout the range of analyte concentrations and test materials to which it is applied. It follows that these features, together with a statement of any fitness-for-purpose criteria, should be completely specified before any validation takes place.