光度法测定粉煤灰中镓的研究-分析化学专业论文.docxVIP

ABSTRACT ABSTRACT ABSTRACT With the continuous development of science and technology, the scattered gallium metal is used widely. Generally, gallium content in fly ash is 12~230 μg/g, which is value of recycle. Therefore, accurate determination and extraction of gallium in fly ash are important. Spectrophotometry is simple, rapid, sensitive, accurate, simple operation, low running cost, and wide applied method. However, the sample pretreatment step is required to detect gallium metal using spectrophotometry. Especially, the employed chromogenic, extracting and hyperchromic agents are organic reagents, which are harmful. In this paper, a method determination of gallium with high sensitivity, good accuracy, and simple process was discussed by using low toxic or non-toxic reagents in the pretreatment progress. Main projects and results are as follow: Use of organic reagents for spectrophotometric determination of gallium with Rhodamine B, the spectrophotometry of determination gallium in fly ash was obtained in the presence of polyethylene glycol by butyl acetate extraction agent, to replace toxic reagents benzene and toluene. The target of substitute for toxic reagents in butyl Rhodamine B and Rhodamine B photometry gallium test was successfully completed, and this new method has high sensitivity and good accuracy compared with national standard method. This method was employed to test in real samples, and obtained satisfy results. The pink compounds of Butyl Rhodamine B and gallium(Ⅲ) have its maximum absorption at 558nm with the apparent molar absorptivity of 2.79×105L·mol-1·cm-1. Beer′s law is kept in the range of 0.5~8mg·L-1 of Ga(Ⅲ), and the detection limit (3S/N) is 0.03mg·L-1. The red complex of Rhodamine B and gallium(Ⅲ) have its maximum absorption at 555nm with the apparent molar absorptivity of 7.8×104L·mol-1·cm-1. Beer′s law is kept in the range of 1~10mg·L-1 of Ga(Ⅲ), and the detection limit (3S/N) is 0.08mg·L-1. The orthogonal test applied to optimiz