Pure & Appl. Chem., Vol. 71, No. 2, pp. 337–348, 1999. Printed in Great Britain.  1999 IUPAC 337 INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY ANALYTICAL, APPLIED, CLINICAL, INORGANIC AND PHYSICAL CHEMISTRY DIVISIONS INTERDIVISIONAL WORKING PARTY FOR HARMONIZATION OF QUALITY ASSURANCE SCHEMES FOR ANALYTICAL LABORATORIES* HARMONISED GUIDELINES FOR THE USE OF RECOVERY INFORMATION IN ANALYTICAL MEASUREMENT (Technical Report) Resulting from the Symposium on Harmonisation of Quality Assurance Systems for Analytical Laboratories, Orlando, USA, 4–5 September 1996 held under the sponsorship of IUPAC, ISO and AOAC INTERNATIONAL Prepared for publication by MICHAEL THOMPSON 1 , STEPHEN L. R. ELLISON 2 , ALES ˘ FAJGELJ 3 , PAUL WILLETTS 4 AND ROGER WOOD 4 1 Department of Chemistry, Birkbeck College (University of London), London WC1H 0PP, UK 2 Laboratory of the Government Chemist, Queens Road, Teddington, Middlesex TW11 0LY, UK 3 International Atomic Energy Agency, Agency’s Laboratories Seibersdorf, A-2444 Seibersdorf, Austria 4 MAFF Food Science Laboratory, Norwich Research Park, Colney, Norwich NR4 7UQ, UK *Membership of the Working Party during 1995–99 was as follows: Chairman: M. Parkany, 1995–97, (Switzerland); A. Fajgelj, 1997– , (IAEA, Austria); Members: T. B. Anglov (Denmark); K. Bergknut (Norway); K. G. Boroviczeny (Germany); Carmen Camara (Spain); K. Camman (Germany); Jyette Molin Christensen (Denmark); S. Coates (AOAC Int. , USA); W. P. Cofino (The Netherlands); P. De Bievre (Belgium); T. D. Geary (Australia); T. Gills (USA); A. J. Head (UK); J. Hlavay (Hungary); D. G. Holcombe (UK); P. T. Holland (New Zealand); W. Horwitz (USA); A. Kallner (Sweden); H. Klich (Germany); J. Kristiansen (Denmark); Helen Liddy (Australia); E. A. Maier (Belgium); H. Muntau (Italy); C. Nieto De Castro (Portugal); E. Olsen (Denmark); Nancy Palmer (USA); S. D. Rasberry (USA); M. Thompson (UK); M. J. Vernengo (Argentina); R. Wood (UK). Republication or reproduction of this report or its storage and/or dissemination by electronic means is permitted without the need for formal IUPAC permission on condition that an acknowledgement, with full reference to the source along with use of the copyright symbol , the name IUPAC and the year of publication are prominently visible. Publication of a translation into another language is subject to the additional condition of prior approval from the relevant IUPAC National Adhering Organization.