Last Updated: 17-10-2019 11:18
Within the framework of the HBM4EU project, an External Quality Assurance Scheme (EQUAS) was organized and conducted for the analysis of cadmium in blood.
The study was performed from May 2019 to June 2019.
The HBM4EU QAU selected six expert laboratories for cadmium in blood. Four expert laboratories were from Europe (HBM4EU consortium) and three of them also participated as candidates. Two expert laboratories were from outside Europe (Japan, USA).
In total, 56 laboratories were invited for this third round, of which 37 laboratories from 22 countries registered.
The participation in this EQUAS was satisfactory; 36 out of 37 laboratories (97%) submitted their results.
In May 2019, twelve different test samples consisting of 3 mL blood spiked with cadmium at two different concentrations (Cdlow, Cdhigh), six of each concentration, were prepared and sent to the participating expert laboratories for analysis in duplicate. Each candidate laboratory got two samples, one of each concentration for single analysis.
Homogeneity and stability assessment of the control materials confirmed that the materials were adequately homogeneous and stable.
The expert assigned values were calculated by averaging the values obtained by the expert labs.
The proficiency of the laboratories was assessed through Z-scores calculated using the mean concentration as established by expert laboratories as assigned value, and a fixed fit-for-purpose relative target standard deviation (FFP-RSDR) of 25%.
The evaluation of Cdlow showed that 83% of the results were satisfactory, 6% were questionable and 11% were unsatisfactory. The evaluation of Cdhigh showed that 89% of the results were satisfactory, 3% were questionable and 8% were unsatisfactory.