This Technical Report (type 2) is a guide with the objective of providing detailed and comprehensive guidance on a coordinated programme of within-laboratory and between-laboratory quality control for ensuring the achievement of results of adequate and specified accuracy in the analysis of waters and associated materials.

This Technical Report and its annexes are applicable to the chemical and physicochemical analysis of natural waters (including sea water), waste water, raw water intended for the production of potable water, and potable water. It is not intended for application to the analysis of sludges and sediments (although many of its general principles are applicable to such analysis) and it does not address the biological or microbiological examination of water. Whilst sampling is an important aspect, this is only briefly considered.

Analytical quality control as described in this Technical Report is intended for application to water analysis carried out within a quality assurance programme. This Technical Report does not address the detailed requirements of quality assurance for water analysis.

The recommendations of this Technical Report are in agreement with the recommendations of established quality assurance documentation (for example ISO Guide 25 and EN 45001). A discussion of quality systems in water analysis is provided in clause 4 to set in context the recommendations on quality control.

This Technical Report is applicable to the use of all analytical methods within its field of application, although its detailed recommendations may require interpretation and adaptation to deal with certain types of determinand (for example non-specific determinands such as suspended solids or biochemical oxygen demand). In the event of any disparity between the recommendations of this Technical Report and the requirements of a standard method of analysis, the requirements of the method should prevail.

The basis of the Technical Report is to ensure the achievement of results of adequate accuracy by adherence to the sequential stages of analytical quality control shown in figure 1.