铁(Ⅲ)-硫氰酸钾体系光度法测定食品样品中EDTA-2Na含量  

Spectrophotometric determination of EDTA-2Na content in food with iron(Ⅲ)-potassium thiocyanate system

作　　者：沙鸥[1] 马卫兴[1] 

机构地区：[1]淮海工学院化学工程学院,江苏连云港222005

出　　处：《中国调味品》2010年第8期96-98,101,共4页China Condiment

基　　金：江苏省高校自然科学研究计划资助项目(05KJB150003);江苏省海洋生物技术重点建设实验室基金资助项目(2005HS010);淮海工学院自然科学研究课题资助项目(Z2007045)

摘　　要：建立了一种快速稳定、简便的测定微量乙二胺四乙酸二钠盐的方法。基于EDTA-2Na与Fe3+能生成稳定的FeY,过量的Fe3+与硫氰酸根反应生成血红色的配合物,EDTA-2 Na的加入使与硫氰酸钾反应的Fe3+浓度降低,从而使Fe3+与硫氰酸根络合物的吸光度下降,在485 nm波长下,0.5～22.5μg/mL范围内EDTA-2Na的加入量与体系吸光度的改变量成正比,线性回归方程为A485=0.02497p(μg/mL)+0.03472,线性相关系数为0.9990,表观摩尔吸光系数为5.143×103L.mol-1.cm-1。该法用于食品样品中EDTA-2Na含量的测定,结果满意。A new simple,rapid method for the determination of ethylene diamine tetraacetic acid disodium salt content with iron（Ⅲ）-potassium thiocyanate system was developed in this paper.As the [Fe（C2O4）3]3-is more stable which formed between Iron（Ⅲ） and EDTA-2Na,the absorbance of the red complex formed by the reaction between iron（Ⅲ） and potassium thiocyanate in the NaAc buffer solution was deceased when the EDTA-2Na was added quantitatively.Good linearity was observed over the range of 0.5～22.5 μg/mL at 485 nm.The proposed method has been applied to the determination of EDTA-2Na in food with satisfactory results.

关 键 词：乙二胺四乙酸二钠盐(EDTA-2Na) 硫氰酸钾 光度法 

分 类 号：TS207.3[轻工技术与工程—食品科学]