Direct determination of fluorine in niobium oxide using slurry sampling electrothermal high-resolution continuum source molecular absorption spectrometry

摘要: Aiming for a round-robin test, new method the direct determination of fluorine in niobium oxide has been developed. It is based on use high-resolution molecular absorption spectra calcium mono-fluoride (CaF) generated graphite tube, combined with slurry sampling technique. The measurement was performed at 606.44 nm CaF rotational line. By using tubes zirconium carbide (ZrC) modified platform, sensitivity improved by factor 20, and no additional chemical modifier necessary. Generally, non-spectral interferences were observed presence HCl, H2SO4, H3PO4. For spectral interference occurred due to an overlap CaCl. However, absence these mentioned substances current material, such do not exist this application. characteristic mass found line 0.1 ng; limit detection 5 mg per kg solid sample (3σ criterion). results obtained within range certified values. Comparing classical as pyrohydrolysis-photometric method, developed showed clear advantages regarding specificity. time requirement one analysis strongly shortened from several hours only some minutes.