Use of accumulated proficiency testing scheme results to evaluate laboratory performance in forensic ethanol analysis
Marcellé Archer, Dominique N. Marajh, Maria S. Visser and Maria Fernandes-Whaley
J. Chem. Metrol. (2017), 11:2 ; 31-39
National Metrology Institute of South Africa, Private Bag X34, Lynnwood Ridge, 0040, South Africa
Abstract: In 2004, the National Metrology Institute of South Africa, NMISA (then the National Metrology Laboratory of the CSIR, South Africa) was requested by forensic testing laboratories to coordinate a proficiency testing scheme for the determination of ethanol in blood. This led to an annual proficiency testing scheme where the test materials used are aqueous ethanol certified reference materials prepared and certified by NMISA. This article describes the development of the scheme and the progress made by the regular participants in the scheme over twelve years. The ethanol concentrations of the test samples were between 0.01 g/ 100 g and 0.6 g/ 100 g. The measurement uncertainty and the expected method performance were conveniently estimated from the data collected over the years.
Keywords:Ethanol; proficiency testing; blood alcohol analysis; metrological traceability. © 2017 ACG Publications. All rights reserved.