Raporty IChTJ. Seria B no. 2/2007
Halina Polkowska-Motrenko, Jakub Dudek, Ewelina Chajduk
Proficiency test PLANTS 7: Determination of As, Cd, Cr, Cu, Hg, Pb, Se and Zn in dry mushroom powder - champignon has been described. The proficiency test has been provided by the Institute of Nuclear Chemistry and Technology with cooperation with POLLAB-CHEM/EURACHEM-PL and REFMAT Society according to ISO/IEC Guide 43-1:1997 and IUPAC International Harmonized Protocol (2006). Testing material was prepared from home-grown mushrooms which were air dried, milled and sieved. Particle fraction below 1 min was collected and bottled in 20 g portions. Homogeneity testing shown that the material was homogenized for sample mass at least 500 mg. Assigned (reference) values and their uncertainties were established on the basis of the results of analyses provided by 5 reference laboratories. The testing samples were send to 29 laboratories participating in the proficiency test. The results supplied by the participants were statistically evaluated. Values of z-score, zeta-score and En numbers were used for the evaluation of the participating laboratory performance.