研究了在pH2.76氨基乙酸-盐酸缓冲溶液中,Fe³⁺对H₂O₂氧化2,4-二氨基苯酚(DAP)褪色具有催化作用,游离F^-离子与Fe³⁺形成的稳定络合物 [FeF₆]^3-可阻抑催化作用,阻抑程度与F-量线性相关。基于此,建立了测定微量F^-的催化光度分析的新方法。结果表明,有色溶液的最大吸收波长为500nm,测定的线性范围为0.0～9.0mg/L,检出限为0.09mg/L,RSD(n=6)5%。灵敏度高、选择性好、分析速度快,应用于电厂废水和自来水中微量F^-的测定,结果满意。

When the pH value of glycine-HCl buffer solution is 2.76,Fe³⁺ catalyzes strongly the fading reaction of 2,4-diamonophenol(DAP) by oxidizing with H₂O₂.Free F^- ions and Fe³⁺ form stable complexes [FeF₆]^3-,thus reducing its catalytic effect and its reducing extent is liner with the concentration of F^-.Based on this study,a rapid and simple catalytic spectrophotometric method for the determination of F^- ions has been developed.The results show that the range of determination is0.0～9.0mg/L for F^-,the detection limit is0.09 mg/L for F^-,and RSD(n=6)5%.The method has been applied to the determination of trace fluoride in power plants wastewater and running waters with satisfactory results.