Last Updated: 12-02-2020 9:54
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 September 2019 to October 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 fourth round, of which 21 laboratories from 12 countries registered.
The participation in this EQUAS was satisfactory; 18 out of 21 laboratories (86%) submitted their results.
In September 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. 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 88% of the results were satisfactory, 12% were questionable and none were unsatisfactory. The evaluation of Cdhigh showed that 100% of the results were satisfactory.