Determination of the Iron in the Spinach by Spectrophotometry

To improve the method of determination of the iron in the spinach by spectrophotometry.According to the characteristics of the experiment,sample through the method of dry digestion or the method of wet digestion,in the HAc-NaAc buffer solution(pH = 5),the stationary ternary complex Fe(Ⅱ)-Phen-Triton is red,the maximum absorption of the complex is at 510 nm,and the apparent molar absorption absorptivity of the complex is 1.2 × 105 L ·mol-1·cm-1.Beer's law is obeyed for Fe(Ⅱ) in the range of 0.5～12 μg/mL.This method can be applied to the microanalysis of Fe(Ⅱ) in the spinach sample.The percent recovery ranges from 97.1 % to 98.0 %.Besides,the iron content of spinach leaves is about 4.5 μg/g and the iron content of spinach stem is about 8.0 μg/g.