[en] A simple, effective and accurate method of decomposition, dissolution and separation for the spectro-photometric determination of Nb and Ta in Nb- Ta and tin slag samples is described. Nb-Ta samples are fused with (1:1) mixture of sodium di- hydrogen ortho-phosphate and tetra sodium pyrophosphate in a Pt crucible. The melt is dissolved in distilled water. Tin slag samples are treated with HF + HNO₃ to remove Si and then evaporated with HNO₃ and fumed with H₂SO₄ to remove HF and HNO₃ completely. Acid hydrolysis was carried out in presence of SO₂ solution. Nb and Ta are precipitated quantitatively from HCl solution. The precipitate is filtered, dried and again fused with the same flux and dissolved in distilled water to get a clear solution. Suitable aliquots are taken for the analysis of Nb by H₂O₂ and Ta by malachite green method. Iron interferes in the analysis of Nb by H₂O₂ method. Hence the optimum parameters for quantitative precipitation of Nb and Ta and complete removal of Fe like volume of sample solution, HCl concentration and effect of SO₂ water are investigated. The validity of the method is checked with CRMs IGS-33, IGS-34 and synthetic mixtures of varied composition conforming to Nb- Ta and Sn slag. For tin slag samples validity of results were checked by comparing with ICP AES analysis without separation. The RSD of the method varies between 1-5% depending on the concentration. (author)