The evaluation of measurement uncertainty from method validation studies -Part 2: The practical application of a laboratory protocol

A protocol has been developed illustrating the link between validation expe riments and measurement uncertainty evaluation. The application of the prot ocol is illustrated with reference to a method for the determination of thr ee markers (CI solvent red 24, quinizarin and CI solvent yellow 124) in fue l oil samples. The method requires the extraction of the markers from the s ample matrix by solid phase extraction followed by quantification by high p erformance liquid chromatography (HPLC) with diode array detection. The unc ertainties for the determination of the markers were evaluated using data f rom precision and trueness studies using representative sample matrices spi ked at a range of concentrations, and from ruggedness studies of the extrac tion and HPLC stages.