- Report #: NT TR 569 Edition 6 – English
- Approved: March 2026
- Author(s): Bertil Magnusson, Håvard Hovind, Mikael Krysell, Ulla Lund, Irma Mäkinen, Eskil Sahlin
- Version: Edition 6 – English
Download pdf Size: 1.90 MB
Abstract
The aim of the Trollbook is to give practical guidance on internal quality control for analysts in
their daily work with analytical methods. The main updates for this 6th edition are:
- only two rules recommended for the daily evaluation of the quality control;
- discussing the frequency and how to reduce the false out-of-control situations;
- more focus on target control limits, when possible, based on uncertainty requirements.
- introducing control charts with only action limit.
The first edition of
Internal Quality Control – Handbook of Internal Quality Control in Water
Laboratories was prepared in Nordic cooperation in the 1980s. A major revision was published in
2005, best known under the name
Trollboken. Later it was translated to several other languages
and has been widely used as a tool in chemical laboratories – not only in environmental
laboratories.
During the years since the first edition was prepared, there have been many developments in the
field of analytical quality. Above all, the requirement for accreditation of analytical laboratories
has put pressure on the laboratories to document their analytical quality, and internal quality control
is an important part of this documentation.
Since the accreditation standard ISO/IEC 17025 was introduced, there has been an increased
focus on the concept of measurement uncertainty for both chemical and microbiological methods.
When a laboratory estimates measurement uncertainty for a test method knowledge of the withinlaboratory
reproducibility obtained from internal quality control (intermediate precision) is
essential.
The task of compiling this book has been made possible by financial support from Nordic
Innovation Centre/Nordtest, Swedish Environmental Protection Agency and Trollboken AB.
This 6th edition of the handbook TR569 can be downloaded from www.nordtest.info.
Frequently Asked Questions (FAQ) about Nordtest handbooks can be found at
www.trollboken.se under menu item FAQ.