分光光度法研究Bi(Ⅲ)与V(V),W(Ⅵ)和U(Ⅵ)的正丙醇析相萃取分离

Spectrophotometric Study on Extraction of Bi(Ⅲ) from V(Ⅴ),W(Ⅵ) and U(Ⅵ) by Phase Separation with n-Propyl Alcohol

研究了以碘化钾为络合剂,正丙醇-水体系析相萃取分离和富集铋的行为及与一些金属离子分离的条件。试验结果表明,氯化钠能使正丙醇的水溶液分成两相,在分相过程中,Bi(Ⅲ)与碘化钾生成的BiI_4^-与质子化正丙醇(C_3H_7OH_2^+)形成的缔合物[BiI_4^-][C_3H_7OH_2^+]能被正丙醇相完全萃取。当正丙醇、碘化钾和氯化钠的浓度分别为30%(V/V)、6.0×10^(-3)mol·L^(-1)、0.20g·mL^(-1),pH为2时,Bi(Ⅲ)的萃取率达到99.2%以上,V(Ⅴ),W(Ⅵ)和U(Ⅵ)基本不被萃取,实现了Bi(Ⅲ)与上述金属离子的分离,对合成水样中Bi(Ⅲ)进行分离和测定,结果令人满意。

The behavior and conditions of extraction separation and concentration of bismuth from other metal ions in n-propyl alcohol -water system with potassium iodide as complexing agent were studied. The results showed that the n-propyl alcohol-water solution could be well divided into two phases with the action of sodium chioride. The associated [BiI4-] [C3H7OH2-] formed with C3H7OH2＋ and BiI4-[combined from Bi（ III） and potassium iodide] could be completely extracted during this process. Bi（ III ） could be quantitatively separated from V（ V ） ,W（ VI ） and U（VI） by extraction, and extraction rate of Bi （ II ） were over 99. 2%, when the concentrations of n-propyl alcohol, potassium iodide and sodium chloride in solution were 30%（V/V）, 6. 0 × 10-3 mol · L- 1 and 0.20g · mL-1,respectively,with pH value of 2. This method was applied to the extraction separation of bismuth in the sample of synthetic water with satisfactory results.