Studies On The Complexation Reaction Between Glycine And Ferrous Ions

In this paper, the complexation reaction between glycine and ferrous ions was studied by UV-Vis spectroscopy. The effect of complexation reaction conditions, such as temperature, ionic strength, plex-ratio and pH value were studied. The results showed that the rate constant of the complexation reaction was the largest, and the temperature had no significant effect on the rate constant, by given condition that the ionic strength I =0.02; the complex rate of glycine and ferrous ions (Gly/Fe) is 4:1; pH=5. The complexation reaction between glycine and ferrous ions was second-order reaction, whose activation energy Ea is 4.662KJ/mol, and free energyΔG≠is 2.188KJ/mol. The possible reaction mechanism for the complexation between glycine and Fe(II) was proposed which could be referenced by the preparation of high purity ferrous glycine.The synthesizing conditions of ferrous glycinate chelate using ferrous chloride and glycine as raw materials were studied in this paper. The result showed that the constitution of product and the yield rate of ferrous glycinate chelate were considerably affected by pH, the molar ratio of glycine to ferrous, and the amount of antioxidant. The optimized reaction condition was pH=5.0, the molar ratio of 2:1. Organic solvent was used to extracted ferrous glycinate chelate and then it was precipitated in ethyl alcohol absolute. Consequently, the chelate can be purified and analyzed by common chemical method. Extraction solvent was also evaluated. The effect of volume ratio of organic solvent on recovery rate of ferrous glycinate chelate was studied. The highest recovery rate of ferrous was obtained at 8:11 of ethyl alcohol absolute to extract ferrous glycinate chelate. The product was characterized by IR and DSC.