【摘要】 研究了在HCl介质中,痕量铁离子催化过氧化氢氧化溴百里酚蓝和孔雀绿褪色的指示反应,通过测量430nm和615nm处催化体系和非催化体系吸光度的变化,建立了双波长双指示剂催化动力学光度法测定痕量铁的新方法。在最佳实验条件下,铁的质量浓度在0~0.017μg/mL范围内与ΔA呈线性关系,ΔA=ΔA430+ΔA615,线性方程为ΔA=35.70ρ(μg/mL)+0.03756,r=0.9988,方法检出限为9.2×10-11g/L。大部分常见离子允许量较高,该方法已用于水样中痕量铁的测定,测定结果与原子吸收光谱法一致。更多还原

【Abstract】 A new dual-wavelength dual-indicator catalytic kinetic spectrophotometric method for the determination of trace iron(Ⅲ) was studied.The method was based on the iron(Ⅲ) catalyzing the fading reaction of bromocresol blue and malachite green oxidized by hydrogen peroxide in the HCl medium. The absorbance of catalytic and uncatalytic systems at 430 nm and 615 nm were measured. Under the optimum conditions,the linear range of the determination is 0-0.017 μg/mL. The linear regression equation is ΔA=35.70ρ(μg/mL)+0.037 56 with correlation coefficient of 0.998 8,and the detection limit is 9.2×10-11 g/L. The method has been used to the determination of trace iron in tap water,the results were good agreement with the values obtained by atomic absorption spectrometry.更多还原