Citation

Schmitt G, Aderjan R. Blutalkohol 2004; 41(4): 299-318.

Affiliation

Inst. fur Rechtsmed./Verkehrsmed., Universitat Heidelberg, D-69115 Heidelberg, Germany.

Copyright

(Copyright © 2004, International Committee on Alcohol, Drugs and Traffic Safety and Bund gegen Alkohol und Drogen im Straßenverkehr, Publisher Steintor Verlag)

DOI

unavailable

PMID

unavailable

Abstract

According to the ISO 17025 the method validation procedure corresponds to in-house aptitude testing. Testing the blood alcohol determination was performed using headspace gas chromatography and the ADH enzymatic method and data obtained from daily case study. Given the fact that there is no definition of a validation procedure mentioned in the German guidelines for blood alcohol determination, our validation was accomplished according to the guidelines for forensic-toxicological investigations as introduced by the GTFCh (Gesellschaft fur Toxikologische und Forensische Chemie). They were originally designated for gas chromatography and mass-spectrometry measurements. Our work shows that the GTFCh guidelines can be fulfilled after appropriate adaptation of individual validation parameters. However, with the current calibrators used at a pre-determined level of significance of 99%, the limit of determination (LOD) is 0,08 g/L for the GC-method and 0,3 g/L for the ADH- method respectively. According to its definition, the measurement inaccuracy at the LOD is 33,3%. The lower the level, the higher the measurement inaccuracy, which means that with current calibrators, the levels below the LOD can no longer be determined with sufficient accuracy. Lower concentration measurement, a modified calibration range or a lower level of significance of perhaps 95% would contribute to the improvement of data. We suggest using these validation statistics and evaluation, which proved to be suitable for the forensic blood alcohol determination, too.