Study on synthesis technology of iron complex of Brassica rapa L.polysaccharide
Objective The synthesis process of Brassica rapa L.polysaccharide iron(Ⅲ)[BP-Fe(Ⅲ)]complexes was studied.Methods Ferric chloride and Brassica rapa L.polysaccharide were used as react-ants to synthesize a Brassica rapa L.polysaccharide iron(Ⅲ)complex.The effects of pH,reaction time,temperature,and the mass ratio of sodium citrate and polysaccharides on the BP-Fe(Ⅲ)complexes were systematically studied by single factor method.Orthogonal experiments were used to screen the optimal synthesis process of BP-Fe(Ⅲ)complexes.The content of iron in BP-Fe(Ⅲ)complexes was determined by UV method.Iron ion characteristic reaction experiments were performed.The BP-Fe(Ⅲ)complex and turnip polysaccharide were characterized by infrared spectroscopy.Results The optimal synthesis condi-tions of BP-Fe(Ⅲ)complexes were obtained from orthogonal experiments:the mass ratio of sodium cit-rate and Brassica rapa L.polysaccharide was 2∶1,the reaction time was 180 min,the reaction solution pH was 6,the reaction temperature was 60℃,and the iron content was 4.53%.The order of effect on the iron content in BP-Fe(Ⅲ)complexes were as follows:sodium citrate and polysaccharide mass ratio(A)>reaction solution pH(B)>reaction time(C)>reaction temperature(D).The results of iron ion charac-teristic reaction experiments showed that Brassica rapa L.polysaccharides and iron complexes were syn-thesized as stable complexes.The infrared spectroscopy showed that the basic structure of Brassica rapa L.polysaccharides did not change significantly after forming a stable complex with iron.Conclusion This method is simple to operate,low cost and suitable for the synthesis of polysaccharide iron complexes.