Browsing by Author "Çorumluoğlu, Orhan"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- ItemCollaborative study into the analysis of total selenium and selenium valence states in glass - a general method by hydride generation atomic absorption spectrometry and photometry : Report of the International Commission on Glass (ICG) Technical Committee 2 "Chemical Durability and Analysis"(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 2000) Guadagnino, Emanuel; Çorumluoğlu, OrhanWhilst the determination of total selenium in glass is of great relevance to environmental purposes, the measurement of the oxidation states of selenium which may arise under different redox conditions may contribute to clarify the mechanisms of colour formation. In the proposed method, the determination of total selenium is carried out by hydride generation atomic absorption spectrometry (HGAAS) on three different glasses covering the range of selenium content between 10 and 130 mg/kg of glass. To prevent losses during the decomposition step, selenium is converted into a nonvolatile form as selenate (Se6+). When the sample is decomposed, the HCl Solution (c(HC1) = 10 mol/l) is made and selenium is pre-reduced to Se4+ by heating for 2 h at 80 °C. The determination of selenium oxidation states requires a stepwise approach. The measurement of Se0 is based on its insolubility in HF. After the sample is decomposed, Se0 is filtered off, dissolved from the filter with a HBr-Br2 mixture and finally measured by HGAAS. Se4+ and Se6+ are recovered in the filtrate of the same sample and determined together after conversion of Se4+ into Se6+. Se4+ is determined in the same filtrate by photometry with o-phenylenediamine (OPDA).
- ItemDetermination of coloring elements in the glass raw materials limestone and dolomite by flame atomic absorption spectrometry : Report of the International Commission on Glass (ICG) Technical Committee 2 "Chemical Durability and Analysis"(Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1997) Çorumluoğlu, Orhan; Guadagnino, EmanuelΑ method is described for the determination of impurities such as iron, chromium, manganese, nickel, cobalt and copper in the glass raw materials limestone and dolomite. The proposed method involves the direct measurement technique in aqueous Solution by flame atomic absorption spectrometry. It has been proved to be an accurate and quick method for analyzing concentrations normally found in these raw materials.