Wang X.,Research Institute No 240 |
Wang Y.-X.,Research Institute No 240 |
Li H.-G.,Research Institute No 240 |
Li Y.-H.,Research Institute No 240
Yejin Fenxi/Metallurgical Analysis | Year: 2014
Potassium hydride fluoride was used to fuse sample from low temperature to 900°C in order to fracture mineral crystal structure, then hydrofluoric acid and sulfuric acid were used to decompose the sample thoroughly. After the uranyl complex in the sample was excited by the UV pulse, the fluorescence intensity of uranium was proportional to the concentration. Accordingly, a direct determination of uranium in zircon sand by UV pulse-induced fluorescence method was established. The influence factors of the method were studied and the optimal working conditions were selected as follows: the sample solution temperature should be keep at 13-20°C; the pH of the sample solution should be controlled at 7; the standard addition solution concentration should be 0.5 μg/mL uranium standard solution when standard addition method was used. Besides, the interference of coexisting elements was tested. It was found that, within relative error of ± 5%, the determination of 0.001 mg of uranium was not affected by 2.5 mg of Zr(IV), 0.8 mg of Si(IV), 0.065 mg of Hf(IV), 0.007 5 mg of Ca2+ and Al3+, 0.75 μg Mn2+, 0.015 μg of Eu2+ and Dy3+, but iron more than 0.025 mg would produce negative interference which could be eliminated through solution dilution method. The method was used to determined uranium in British chemical standard BCS 388, SARM 13 and SARM 62. The results were consistent with the certified values.
Cai J.-J.,Northeastern University China |
Xu Y.,Northeastern University China |
Wang Y.-X.,Research Institute No 240
Yejin Fenxi/Metallurgical Analysis | Year: 2012
A simultaneous determination method of 210Pb, 210Bi and 210Po in rock and sol by α, β particle counter method after enrichment of 210Bi and 210Po by nickel-plated sheet was proposed. By the optimization and selection of acidity, volume, temperature and reducing agent for solution preparation, the possible interference of coexisting dements and isotopes were eliminated effectively. The self-plating time was shortened to 40 min. Under the optimal conditions, the calibration curves of 210Po, 210Bi and 210Pb were established with correlation coefficient in the range of 0.9983-0.9997. The linear range was 1.0 × 10 -3-1.0 × 10 2 Bq. The detection limit of 210Po, 210Bi, 210Pb was 6 × 10 -4 Bq/g, 6 ×10 -3 Bq/g and 6 ×10 -3 Bq/g, respectively. The precision of method (RSD, n=11) was better than 1.6 The recoveries of standard addition were 95%-105%. The proposed method realized the simultaneous and rapid determination of 210Pb, 210Bi and 210Po in rock and sol.