Spectrocheraical (GFAAS, ICP-OES) methods were elaborated for the determination of Cr, Er, Mo, Nd and V dopants in bismuth tellurite optical crystals. The samples were dissolved in hydrochloric acid for the analysis. Signal depression interference effects in the GFAAS method were significant at bismuth tellurite concentrations higher than 10-4 and 7.5 × 10-4 mol/l for the longitudinally and transversally heated atomizers, respectively. The matrix effects were, however, smaller for integrated absorbance than for peak absorbance signals. The characteristic masses increased strongly in the order of Cr, Mo, V, Er and Nd, as well as the corresponding limit of detection values. The optimal pyrolysis and atomization temperatures were increased by the addition of oxoacids to the sample solutions. The mixture of bismuth tellurite and triammonium citrate in hydrochloric acid medium resulted in approximately doubled peak absorbance values for chromium and an increased precision as well. The volatility of the matrix components, compared to the analytes, were significantly higher, which could be utilized for the selective removal of the matrix by distillation. Thus, a pre-concentration of the dopants with multiple dosing could be attained in the graphite tube, to realize an improved detection power for all the analytes determined.
|Number of pages||9|
|Journal||Magyar Kemiai Folyoirat, Kemiai Kozlemenyek|
|Publication status||Published - Feb 1 2002|
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