核固红光度法测定乳制品中微量铬  

Spectrophotometric Determination of Trace Chromium in Dairy Products Using Nuclear Fast Red

作　　者：刘英红[1] 马卫兴[1] 斯琴高娃[1,2] 

机构地区：[1]淮海工学院化学工程学院,江苏连云港222005 [2]江苏省海洋资源开发研究院,江苏连云港222005

出　　处：《食品科学》2012年第24期283-285,共3页Food Science

基　　金：淮海工学院自然科学研究项目(2010150014;2010150018);江苏省海洋资源开发研究院科技开放基金项目(SIMR10E07)

摘　　要：建立核固红光度法测定乳制品中微量铬的新方法。在盐酸介质中,铬(Ⅵ)能够氧化核固红而使溶液褪色,且褪色程度与铬(Ⅵ)的质量浓度在一定范围内呈线性关系,据此可以测定铬(Ⅵ),若将铬(Ⅲ)在NaOH溶液中以H2O2氧化成铬(Ⅵ),即可测定总铬,实现铬(Ⅵ)与铬(Ⅲ)的同时测定。在最大吸收波长560nm处,Cr(Ⅵ)的质量浓度在0.2～1.6μg/mL范围内符合比尔定律,表观摩尔吸光系数为2.2×104L/(mol.cm)。方法用于几种乳制品中Cr(Ⅲ)和Cr(Ⅵ)的同时测定,结果与二苯碳酰二肼光度法测定结果一致。A new spectmphotometric method for the simultaneous detemaination of chromium （Ⅲ） and chromium （Ⅵ） in dairy products was proposed. This method was based on the oxidative decoloration of nuclear fast red by chromium （Ⅵ） in hydrochloric acid solution, which is linearly related to chromium （Ⅵ） concentration in a certain range. The oxidization of chromium （III） to chromium （Ⅵ） by hydrogen peroxide in sodium hydroxide solution allows the determination of total chromium and the consequent calculation of chromium （Ⅲ）. The wavelength of maximum absorbance was 560 nm with an apparent molar absorption coefficient of 2.2× 10^4 L/（mol.cm）. The absorbance obeyed Beer-Lambert law over the range of 0.2-1.6 μg/mL for chromium （Ⅵ）. The proposed method was applied to determine chromium （Ⅲ） and chromium （Ⅵ） in several kinds of dairy products and the results were in good agreement with those determined by 1,5-diphenylcarbazide speclrophotometry.

关 键 词：核固红 铬(Ⅲ) 铬(Ⅵ) 分光光度法 乳制品 

分 类 号：O657.32[理学—分析化学]