Synthesis Characterization And Ionization Of Trace Elements Complexes With Mixed Amino Acids/Small Peptides From Protein-containing Wastewater

Amino acid trace elements complexes has the advantages of low productioncost，non-toxic side effects，easily absorbed and can at the same time provides aminoacids supplementation，being better meet the needs of the body than inorganic traceelements．Therefore，the development and utilization of mixed amino acids/smallpeptide microelement chelate will have broad prospects．Because of the lack and highprices of amino acid，so the production of trace elements complexes with single aminoacid be hindered．In addition，a large number of protein-containing wastewateremissions from our country every year， not only does which pollutes theenvironment，but also wastes resources．In order to make full use of the resources，we can synthesize copper（II），zinc（II） complexes with mixed amino acids/smallpeptides from industrial wastewater．This research tried to synthesize trace elementscomplexes with single amino acid and trace elements complexes with mixed aminoacids/small peptides． Finally， ionization behavior of Mixed amino acids/smallpeptides complexes was discussed．It is preliminary understood that the ionizationbehavior of the mixed amino acids/small peptides complexes in acidic conditions．Themain results were as followed：1. The seven kinds of trace elements complexes with single amino acid wassynthesized．using glycine，methionine，lysine，copper chloride，zinc chloride，and manganese acetate as raw materials，trace elements complexes with single aminoacid was synthesized in the liquid phase．Metal content was determined by titrationand the composition of the product was analysed by infrared analysis，elementalanalysis， thermal gravimetric analysis，etc．including copper glycine Cu（Gly）₂·H₂O；zinc glycine Zn（Gly）₂·H₂O； manganese glycine Mn（Gly）₂；copper methionine Cu（Met）₂；zinc methionine Zn（Met）₂；manganese methionine Mn（Met）₂；copper lysineCu（L-Lys）₂Cl₂·2H₂O．In addition to manganese（II） amino acid complexes，the yieldsof the other five kinds of copper（II） and zinc（II） amino acid complexes were greaterthan90%．The physical properties were measured and the data of melting point andconductivity were supplemented．2. The ferrous glycine complex was synthesized．The technological conditions werethat glycine: Iron: acetic anhydride: citric acid=3:1.5:1:1，reaction temperature was70°C，reaction time was8h，pH was4.5．Total iron and ferrous iron content ofproducts were determined，which was19.60%and12.40%．Product placed in adesiccator for20days, ferrous content became12.37%，which indicated that producthas better stability．3. The molecular weight distribution was determined by HPGPC. Molecular weightless than500of Mixed amino acids/small peptides accounted for60%in industrialbone protein wastewater，molecular weight less than500of mixed amino acids/smallpeptides accounted for94%in industrial casing protein wastewater．4. This research used industrial bone protein wastewater and industrial casing proteinwastewater as raw materials. Copper（II），zinc（II） complexes with mixed aminoacids/small peptides in the liquid phase were synthesized．The molar ratio of themixed amino acids/small peptides complexes preparation was optimized，which wasas followed：5mL industrial bone protein wastewater:0.8mmol of copper sulfate（zinc）；5mL industrial casing protein wastewater:0.3mmol of copper sulfate （zinc），The XRD analysis showed that copper existed in the mixed amino acids/smallpeptides complexes have all been chelated． The reaction time and reactiontemperature on the chelating effect is small, the actual production can slightly heated（30℃） and the reaction time was30min and40min, in order to reduce powerconsumption, reduce production costs.5. Ionization behavior of2copper（II） complexes with mixed amino acids/smallpeptides was discussed．Copper（II） complexes with industrial bone protein wastewatercan exist stably，when the pH value is5to4．With the the reduction of pH value，the absorption peak red shift，indicating that the partially solution has ionized with thestrengthening of the solution acid．Copper（II） complexes with industrial casingprotein wastewater was ionized at a pH value of less than5，which indicated the poorstability of copper（II） complexes with casings protease．...