11. Mistakes to avoid

11.1 Never try to validate a method under development

It is essential to remember that validation should always take place after the method has been developed and its operating procedure written. Attempting to carry out validation tests with a method that is still poorly understood could lead to serious disappointment, and the conclusion that it is not valid.

Some results can be surprising or disappointing. In such cases, an explanation must be found. We may suspect the materials used, their state of preservation or a matrix effect. You need to think carefully about the choice of materials, and how they are prepared and preserved. In short, don't underestimate the practical and logistical aspects.