PT-2019-NRL-TE-FASFC Determination of As, Asi, Cd, Pb, Cu, Zn, Cr, Ni in lentils. Final report on the 2019 proficiency test organised by the National Reference Laboratory for Trace Elements in Food and Feed, Cheyns, Karlien, and Waegeneers Nadia , 2019, Tervuren, Belgium, p.31, (2019)