Proficiency Testing Supervisors
Institute of Legal Medicine and Traffic Medicine
University Hospital Heidelberg
Voßstraße 2, D-69115 Heidelberg, Germany
Proficiency Testing Organization
Kiefernweg 4, D-69190 Walldorf, Germany
External Quality Assurance
The GTFCh is organizer of proficiency tests for forensic purposes. The GTFCh proficiency testing is part of an internationally acknowledged accreditation procedure for forensic laboratories according to DIN EN ISO 17025. The scientific and administrative supervisors work voluntarily. Technical and organizational tasks are regulated by the ARVECON GmbH. In cooperation with the executive committee of the GTFCh the coordinators decide:
- type and frequency of proficiency testing
- organizational tasks
- time frame
- criteria for a successful participation
- criteria for obtaining a certificate
- validity of certificates.
Internal Quality Assurance
Proficiency testing is a primarily an instrument for external quality assurance. However, the remaining sample material is still useful for the internal quality assurance. The distribution of this material was delegated to the ARVECON GmbH, e.g. in cooperation with other commercial partners such as ACQ Science, LGC Standards und MEDICHEM. The GTFCh declares expressly that the sample material is neither certified reference material in compliance with the standards (CRM) nor reference material certified by the GTFCh.
Regardless, this sample material identified in suitability for forensic and clinical toxicology or clinical-chemical and other purposes as it is currently the best-characterized reference materials are referred to. For this reason, the GTFCh has a legitimate interest in asking subcontractors to correctly identify this reference sample material and not to distribute it before applicability and concentration specifications have been scientifically examined and approved by the proficiency testing supervisors via the GTFCh's homepage. Any authorisation for the use of data of individual proficiency testing is subject to approval  .
 According to the rules of procedure of the Society for Toxicological and Forensic Chemistry for the cooperation between proficiency test supervisors and proficiency test contractors (Toxichem 2006, 73(2):73-75), for each proficiency test, the proficiency test supervisors receive a copy of the data (for which an electronic back-up exists) after evaluation. The proficiency test data are made available to the proficiency test supervisors. In addition, the publication of the proficiency test results supplied with the certificate, and the results of the other participants both require authorisation of the proficiency test supervisors.