The conditions of decomposition by dry and wet mineralization were verified on certified reference mateials of apple tree leaves (NIST 1515) and human hair (GBW 07601). In the mineralizates, Pb, Cd, Cu, Zn, Fe, Se and As were determined by AAS with flame atomization. The precision of the obtained results was tested by statistical methods. A good agreement of the measured with certified results was attained in microwave and dry mineralization in UniClever and Apion mineralizers, respectively.