External validation of analysis methods

The validation of analytical methods is a major challenge for laboratories today. It stems from the implementation of quality assurance systems and, for this reason, is often perceived as a constraint. This attitude is regrettable, as laboratories have everything to gain from developing analytical methods that deliver results in which we can have confidence. The shift from quantitative to qualitative methods of analysis represents a veritable revolution. All too often, it has been associated with the purchase of a new, more "efficient" piece of equipment, without any thought being given to whether this performance is real in scientific terms.

This is why there are still grey areas in the definition, and consequently the evaluation, of many method performance criteria. The best example is the detection limit, which is widely used (particularly by equipment manufacturers), despite the fact that there are dozens of calculation methods, all of which produce different values. These criteria raise numerous statistical problems that have not always been satisfactorily resolved. It's up to the analysts to ask these questions correctly, so as to obtain a clear answer. For this reason, we believe that standardizing the way in which method quality criteria are calculated is a particularly appropriate approach to this problem.