甲基百里酚蓝分光光度法测定食品中铅  

Spectrophotometric Determination of Lead in Foods with Methyl Thymol Blue

作　　者：邹时英[1] 王蓉[1] 付大友[1] 

机构地区：[1]四川理工学院材料与化学工程学院,四川自贡643000

出　　处：《中国调味品》2012年第9期89-91,共3页China Condiment

摘　　要：目的:探索分光光度法测定食品中痕量铅的方法。方法:建立了以甲基百里酚蓝为显色剂的分光光度法测定铅的体系。结果:在邻苯二甲酸氢钾-氢氧化钠缓冲溶液中,铅与显色剂、溴化十六烷基吡啶形成蓝色络合物,最大吸收波长为605nm,表观摩尔吸光系数ε605为2.6×104 L/mol.cm,铅含量在0～7.2μg/mL范围内符合比耳定律。用于食品中铅含量的测定,相对标准偏差为1.5%～3.2%(n=6),加标回收率为96.3%～102.7%。结论:该方法准确度、精密度良好,操作简便,可用于食品中痕量铅的测定。Objective： The aim was to explore a spectrophotometric method for the determination of trace lead in foods. Method： A spectrophotometric method for the determination of trace lead was de- veloped. It was based on the fact that trace lead reacted with methyl thymol blue in the presence of hrominated cetyl pyridine. Result： In the buffer solution of potassium hydrogen phthalate-sodium hy- droxide,lead could form blue complex with methyl thymol blue（MTB）. The maximum absorption of the complex occurred at 605 nm. The apparent molar absorptivity was 2.6）〈 10^4L/mol · cm and Beer＇ s law was obeyed in the range of 0-7.2μg/mL. Values of RSD（n=6） were found 1.5-3.2%, and values of recovery found by standard addition method were in the range of 96.3-102.7%. Conclu-sion： The method had good accuracy and precision. It was a convenient and reliable method for the de-termination of trace lead in foods.

关 键 词：铅 甲基百里酚蓝 食品 溴化十六烷基吡啶 分光光度法 

分 类 号：TS207.51[轻工技术与工程—食品科学]