【摘要】 研究了在0.2 mol/L柠檬酸介质中,利用钒酸根对溴酸钾氧化乙基紫和萘酚绿B褪色反应同时具有强烈的催化作用,通过650 nm和720 nm波长下测量催化体系和非催化体系的吸光度,建立了一种双指示剂、双波长催化动力学光度法测定钒(V)的新方法。最佳实验条件下,测定钒的线性范围为1.00~80.0μg/L,检出限为1.1×10-10g/mL。对20.0μg/L钒进行12次平行测定的相对标准偏差为2.2%。方法用于面粉和大米中痕量钒的测定,结果令人满意。更多还原

【Abstract】 A dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace vanadium in 0.2 mol/L citric acid medium was studied.It was based on the catalytic effect of vanadium on the oxidation of ethyl violet and naphthol green B by potassium bromate.The absorbance of catalytic system and uncatalytic system were measured at 650 nm and 720 nm.Under the optimum conditions,the linear range of the determination of trace vanadium was 1.00~80.0 μg/L.The detection limit was 1.1×10-10 g/mL and the relative standard deviation(n=12) was 2.2% for 20.0 μg/L vanadium.The method was applied to the determination of trace vanadium in flour and rice with satisfactory results.更多还原