How to validate analytical methods

Abstract The requirement for laboratories to use a `fully validated' method of analysis is now accepted or required in many sectors of analysis. Fully validated means that a method must have been assessed in a collaborative trial. The significance of these requirements is described because analysts will increasingly be required to justify their choice of method in the light of them. In addition, the requirements and procedures that may be used to obtain methods that have been validated `in-house', without full validation through collaborative trial, are also outlined in the article, these pointing the way to international acceptance of such methods in future as the cost of carrying out full validation of methods through collaborative trials becomes prohibitory.