The production of fertilisers is a chemical process which requires a careful chemical characterization of the raw materials, intermediate compounds and the final products. The analytical methods used for the quality control of production must fulfil stringent requirements with respect to accuracy and precision.

This paper describes a programme to evaluate the quality of the analytical results and the analytical standard that can be achieved in routine analytical work. This is usually termed a quality assurance programme. Examples of method improvements are discussed, as well as aspects of the management of the programme.