Toward a quality guide to facilitate the transference of analytical methods from research to testing laboratories: a case study.

At present, there is no single viewpoint that defines QA strategies in analytical chemistry. On the other hand, there are no unique protocols defining a set of analytical tasks and decision criteria to be performed during the method development phase (e.g., by a single research laboratory) in order to facilitate the transference to the testing laboratories intending to adapt, validate, and routinely use this method. This study proposes general criteria, a priori valid for any developed method, recommended as a provisional quality guide containing the minimum internal tasks necessary to publish new analytical method results. As an application, the selection of some basic internal quality tasks and the corresponding accepted criteria are adapted to a concrete case study: indirect differential pulse polarographic determination of nitrate in water samples according to European Commission requisites. Extra tasks to be performed by testing laboratories are also outlined.