摘要
Fe(Ⅲ)与磺基水杨酸在p H=2~3的溶液中形成紫红色配离子,加入适量的VC将溶液中的Fe3+还原成Fe2+,溶液吸光度减小。测定溶液加入VC前后的吸光度分别记为A0、A,其吸光度变化为ΔA=A0-A。以ΔA与VC浓度CVc绘制标准工作曲线。在VC浓度4μg/m L^37μg/m L的范围内,ΔA(y)与CVc(x)的线性回归方程为y=0.018 2x+0.027 1,相关系数为r=0.999 6。利用该法测得梅县沙田柚果肉VC的含量为97.92 mg/100 g,测定相对标准偏差为1.1%,测定回收率95.6%~98.9%(n=5)。
Fe （Ⅲ） ion and sulfosalicylic acid could found purple-red complex at pH value of 2-3,which had maximum absorption wavelength of 502 nm . When Vitamin C was added into the system,the Fe （Ⅲ） ions were reduced to Fe （Ⅱ） ions ,and the purple-red complex＇s absorbance would fall down. The reduction of absorbance （ΔA） had good linear relationship with the contents of Vitamin C from 4μg/mL to 37μg/mL. The linear regression equation was y=0.018 2x＋0.027 1 and the related coefficient was 0.999 6 （n=5）. The concent of Vitamin C in Shatian pomelo pulp was determined by this method which was 97.92 mg/100 g,and the recoveries of the method were 95.6%-98.9%（n=5）,the relatively standard deviation was 1.1%.
出处
《食品研究与开发》
CAS
北大核心
2014年第22期111-114,共4页
Food Research and Development
关键词
Fe(Ⅲ)
磺基水杨酸
褪色光度法
VC
iron（ Ⅲ ）
sulfosalicylic acid
fading spectrophotometry
Vitamin C
