摘要
在pH2.53的氨基乙酸-HCl缓冲体系中,Fe3+对H2O2氧化2,4-二氨基苯酚(DAP)褪色具有催化作用。F-离子与Fe3+形成的稳定配离子[FeF6]3-可抑制褪色作用,抑制作用与F-量呈线性相关。由此建立催化抑制光度法测量微量F-的方法。结果显示,有色溶液的最大吸收波长为500nm,表观摩尔吸光系数为2.3×105L/mol·cm,氟含量在9.0mg/L以内符合比耳定律。该方法选择性好,用于测定桑叶中的氟含量,结果令人满意。
In a mixed acid medium of NH2CH2COOH-HCl of pH2.53, the fading reaction of 2,4-diamonophenol （DAP） with H2O2 could be catalyzed by Fe^3＋. F^- could form a stable complex of [FeF6]^3- with Fe^3＋, which could inhibit the fading reaction. Based on this method, a new spectrophotometric method was formed for determination of F^-. Its maximum absorption is at 500nm and an apparent molar absorptivity is 2.3×10^5L/mol·cm. Lambert-Beer＇s law holds in the concentration range of 9.0mg/L solution is F^-. The method has good selection, and has been applied to the determination of fluoride in mulberry leaves. Its result is satisfactory.
出处
《食品科技》
CAS
北大核心
2006年第7期219-221,共3页
Food Science and Technology
关键词
氟化物
阻抑动力学
分光光度法
桑叶
fluoride
inhibition kinetics
spectrophotometry
mulberry leaves
