作　　者： ; ; ; (张纪文）; (苏志文）; (张圆玲）;

机构地区： 广东药学院公共卫生学院

出　　处： 《冶金分析》 2008年第7期65-68,共4页

摘　　要： 基于0．016mol／L硫酸介质中，痕量钛（Ⅳ）催化H2O2氧化邻硝苯基荧光酮（o-NO2-PF）的褪色反应，建立了测定痕量钛㈣的动力学光度法。在固定加热时间段（8min）后，于550nm处测定o-NO2-PF的吸光度降低值监控反应速率。讨论了酸度、反应物浓度、温度、反应时间、干扰离子等因素的影响。确立了反应的最佳条件，并测定了一些动力学参数，催化反应的表观活化能为81．09kJ／mol。方法检出限为0．064μg／L，工作曲线的浓度线性范围为0～8．0μg／L。在25mL溶液中，测定0．2μg钛（Ⅳ）的相对标准偏差为1．86％（n=11）。方法用于岩石样品中钛㈣的测定，结果与认定值相符，相对标准偏差为1．46％～1．85％。 A spectrophotometric method for the determination of titaniumaV） is described. It is based on the catalytic effect of Ti（Ⅳ） on the oxidation reaction of o-nitrophenylfluorone （o-NO2-PF） and hydrogen peroxide in 0. 016 mol/L H2SO4 medium at 90 ℃. The above catalytic reaction rate is monitored spectrophotometrically by measuring the decrease in the absorbance of o-NO2-PF at 550 nm after heating for 8 min. The influences of the acidity, concentration of reactants, reaction time, temperature and coexisting ions on the reaction are also discussed. The optimum conditions were established and some kinetic parameters were determined. The apparent activation energy of the catalytic reaction is 81.09 kJ/mol. The calibration curve for the recommended method is linear in the range over 0-8.0 μg/L for titanium（IV） and the detection limit of the method is 0. 064 μg/L. The relative standard deviation for 0.2 μg/25 mL titanium（IV） is 1.86 % （n=11）. In combination with solvent extraction separa- tion, the method has been successfully applied to the determination of titanium（Ⅳ） in rock samples. The results are in good agreement with the certified values with the relative standard deviations （RSD） of 1.46 %-1. 85

关 键 词： 动力学光度法 钛 邻硝苯基荧光酮 过氧化氢

领　　域： [理学] [理学]