天然抗坏血酸还原分光光度法测定奶粉中微量铁

Determination of Trace Iron in Milk Powder by Natural Ascorbic Acid Reduction Spectrophotometry

从绿色植物叶中提取天然抗坏血酸作为三价铁的还原剂,建立了微量铁的分光光度测定法。在测定波长510 nm处,测定铁的线性范围为0.0~200.0μg,回归方程为A=0.003 m(Fe^(3+))+0.0035,相关系数r=0.9998,摩尔吸光系数为8.4×10^(3) L·(mol·cm)^(-1)。将该法用于奶粉中铁含量的测定,奶粉样品采用湿法消解,奶粉中铁的测定相对标准偏差为1.04%,加标回收率为98.2%~106.5%,测定结果满意。

Taking natural ascorbic acid extracted from the leaves of green plants as the reducing agent for trivalent iron,a spectrophotometric method for the determination of trace iron is established.The wavelength for determination is 510 nm.The linear range for determination of iron is 0.0~200.0μg with the molar absorption coefficient of 8.4×10^(3) L/(mol·cm)^(-1).The linear equation is A=0.003 m(Fe^(3+))+0.0035 with correlation coefficient of 0.9998.The milk powder samples are dissolved by using wet method,in which iron is determined with the relative standard deviation of 1.04%and the recovery of 98.2%~106.5%.