Required and delivered analytical information:: the need for consistency

The principal aim of this article is to emphasize the need to systematically consider analytical chemistry as an information discipline on the basis of two essential ingredients of analytical quality, namely: chemical metrology and fitness for purpose. To this end, five different types of analytical information (true, referential, delivered, required and perceived) are defined, and binary and ternary relationships among them are discussed. In so doing, crucial analytical facets are precisely placed within the framework of analytical information. The role of the 'client' (viz. the person or body requiring the analytical information) is also systematically considered. (C) 2000 Published by Elsevier Science B.V.