【摘要】 在pH=9.65的NH3-NH4Cl缓冲溶液中,利用Cu2+对H2O2氧化中性红和溴甲酚紫褪色反应具有较强的催化作用,通过测量460nm和590nm波长下催化体系和非催化体系的吸光度,建立了双指示剂、双波长催化动力学光度法测定痕量Cu2+的新方法。方法的线性范围为0.0060～0.072μg/mL,检出限为8.0×10-12g/mL。对Cu2+进行11次平行测定的相对标准偏差为2.9%。方法用于面粉和大米中痕量铜的测定,结果令人满意。更多还原

【Abstract】 A dual-wavelength dual-indicator catalytic kinetic spetrophotometric method for the determination of trace copper was studied. It was based on the catalytic effect of copper on the oxidation of bromocresol purple and neutral red by hydrogen peroxide in NH3-NH4Cl medium at pH=9.65. The absorbance of catalytic system and uncatalytic system were measured at 460 nm and 590 nm,respectively. Under the optimum conditions,the linear range of the determination of trace copper was 0.0060~0.072 μg/mL. The detection limit was 8.0×10-12 g/mL and the relative standard deviation was 2.9% (n=11). The method was applied to the determination of trace copper in flour and rice with satisfactory results.更多还原