摘要
在pH 3.50的酸性条件下,甲基橙（MEO）与Fe（Ⅲ）反应生成具有正、负吸收峰的橙红色离子缔合物,最大正吸收和最大负吸收波长分别位于525nm和415nm,Fe（Ⅲ）的质量浓度在0-2.23mg/L范围内遵从比尔定律,表观摩尔吸光系数分别为6.39×10^4 L/（mol·cm）（正吸收）和2.59×10^4 L/（mol·cm）（负吸收）。当用正、负吸收叠加测定时,灵敏度可提高到8.99×10^4 L/（mol·cm）。该方法用于奶粉中Fe（Ⅲ）含量的测定,相对标准偏差为1.5%-2.1%之间,加标回收率在98.9%-101%之间。
In acidic condition of pH 3.50,methyl orange（MEO）reacts with Fe（Ⅲ）to form an orange red ionassociation complex with positive absorption peak and negative absorption peak.The maximum positive absorption wavelength and maximum negative absorption wavelength are 525 nm,and 415 nm,respectively,and Beer＇s law is obeyed in the range within 0-2.23mg/L of Fe（Ⅲ）,and apparent molar absorptivities（ε）are 6.39×10^4（positive absorption）and 2.59×10^4（negative absorption）L/（mol·cm）,respectively.When the positive and negative wavelengths overlapping absorption spectrometry was used to determine the content of Fe（Ⅲ）,and its sensitivity can be increased to 8.99×10^4 L/（mol·cm）.The method has been applied to the determination of iron in commercially available milk powder,and RSDs（n=6）are in the range of 1.5%-2.1% and values of recovery by standard addition method are in the range of 98.9%-101%.
出处
《实验技术与管理》
CAS
北大核心
2016年第8期71-73,共3页
Experimental Technology and Management
基金
重庆市教委科技基金资助项目(KJ1401226)
长江师范学院科技基金资助项目(2014CXX0185)
关键词
奶粉
Fe(Ⅲ)含量测定
甲基橙
分光光度法
milk powder
determination of Fe（Ⅲ）content
methyl orange
spectrophotometry
