This Technical Specification describes an approach for the validation of physico-chemical analytical methods for environmental matrices.
The guidance in this document addresses two different validation approaches, in increasing order of complexity. These are:
a) method development and validation at the level of single laboratories (intra-laboratory validation);
b) method validation at the level of several laboratories (between-laboratory or inter-laboratory validation), with a focus on methods that are sufficiently mature and robust to be applied not only by a few expert laboratories but by laboratories operating at the routine level.
The concept of these two approaches is strictly hierarchical, i.e. a method shall fulfil all criteria of the first level before it can enter the validation protocol of the second level.
This Technical Specification is applicable to the validation of a broad range of quantitative physico-chemical analytical methods for the analysis of water (including surface water, groundwater, waste water, and sediment). Analytical methods for other environmental matrices, like soil, sludge, waste, and biota can be validated in the same way. It is intended either for analytical methods aiming at substances that have recently become of interest or for test methods applying recently developed technologies.
The minimal requirements that are indispensable for the characterization of the fitness for purpose of an analytical method are: selectivity, precision, bias and measurement uncertainty. The aim of validation is to prove that these requirements are met.