Project Details Revision in the international harmonised protocol for the proficiency testing of (chemical) analytical laboratories

Project No.:
Start Date:
01 October 2001
End Date:
23 January 2006
Division Name:
Analytical Chemistry Division
Division No.:


To review and revise the International Harmonised Protocol for theProficiency Testing of (Chemical) Analytical Laboratories. The firstinternational protocol was adopted by IUPAC in 1993 and published inPure and Applied Chemistry, 1993, 65, 2123-2144. Thisprotocol has been adopted by a number of international organisationsand is used as the basis for the majority of proficiency testing schemescarried out within the analytical community. It is incorporated intolegislation in the food sector most notably by endorsement by the CodexAlimentarius Commission.

It is now appropriate for the protocol to be revised in the light ofexperience of its usage.


The quality of an analytical result for a laboratory depends on a number of functions, only one of which is the intrinsic quality of the analytical method. Other aspects which a laboratory has to address include internal quality control and recovery considerations. All of these aspects (methods, IQC and recovery) have been addressed by IUPAC protocols/guidelines prepared by the Interdivisional Working Party on Harmonisation of Quality Assurance Schemes for Analytical Laboratories. That Working Party has also prepared international guidelines on proficiency testing which now need to be reassessed in the light of experience. In particular, the following should be addressed in a future revision of the protocol:

  • Procedures for the treatment of z-scores when the default value for not detected is within the acceptable range.
  • Further information on the selection of target standard deviations.
  • Further information on the preparation of homogeneity testing material.
  • The treatment of measurement uncertainty considerations by proficiency testing schemes.
  • The use of results from proficiency testing schemes to aid the validation of specific methods of analysis.

The work will be progressed through an International Workshop at which there will be invited presentations followed by discussion on the revision of the protocol prepared by the project co-ordinators.


A draft outcome of this project, i.e. a revised International Harmonised Protocol for the Proficiency Testing of (Chemical) Analytical Laboratories, has been completed. In order to assure that a review by interested bodies and organizations is done prior publication as a Technical Report in Pure Appl. Chem., the draft is here made available for review

> Download full text (draft040317 pdf file – 348KB), and return comments to Dr. Ales Fajgelj <>.

> Nov 2004 report update (pdf file – 12KB)

Project completed – IUPAC Technical Report published in Pure Appl. Chem. 78(1), 145-196, 2006

In addition to this IUPAC International Harmonised Protocol for the Proficiency Testing of (Chemical) Analytical Laboratories, the Interdivisional WP QA is developing a guide for selection and use of proficiency testing schemes for limited number of participants (chemical analytical laboratories) > see project 2005-019-2-500