Study On The Synthesis And Its Property Of Nitroso-hemoglobin

Using duck blood and NaNO₂ as main material, the synthesis of HbNO was studied. Effects of various factors on the synthesis of the pigment were discussed, and main factors were optimized. And then the stability and rheological properties of pigment were also studied, it is benefit for further research. The results showed as follows.1. The method of acetone to determine the content of HbNO can exclude the interference of impurities during response action and could reflect the amount of pigment production more accurately.2. The synthesis conditions of pigment were optimized: The concentration of hemoglobin, NaNO₂ content, ascorbic acid content, pH, temperature and the reaction time which are affecting the synthesis were studied through the single factor experiment. Based on the single factor experiment, the response surface analysis were used to optimize the various conditions of the main factors affecting absorption, the regression equation of the NaNO₂ amount (x₁), ascorbic acid content (x₂) and pH (x₃) on absorbance (Y) can be gotten. The optimum combination of NaNO₂ content, ascorbic acid content and pH is: 0.53 ml, 272.37mg, 4.51, its response to the corresponding value for absorbance 0.91.3.Under the 450-650 nm scan, the spectrum picture of pigment extracted by 80% aqueous acetone are the same as dinitrosyl ferrohemochrome (DNFH) and HbNO reported before, which indicated that the structure of them were similar.4. The experiment of pigment stability showed that: pigment was stable in 40min, and the high temperature over 85℃caused a lot of chromoproteins deposited after 40min which illuminated that a lot of chromoproteins were lost caused by this temperature and heating processing light was a certain impact on pigment stability, but far less than the light pigment of acetone extract of the impact. There was no effect on pigment under short time ultraviolet radiation.Cu²⁺ and Ag⁺ have a greater impact on pigment solution, when the two are put into soon there have joining muddy; Zn²⁺ and Fe³⁺ have little effect on the stability of solution. Ascorbic acid was relative to the stability of pigment, but the affection was not prominent. On the other side, saccharose and glycerin boost up the stability of pigment.5. The rheological properties of pigment were studied, The results showed as follows: when temperature is 25℃, 12% of the pigment solution is the fake plastic fluid of non-Newtonian fluids, non-Newtonian index is n=0.58, consistency coefficient is K=0.63; The sticky flow activation energy of 12% of the pigment solution is 28.38 kJ/mol; when temperature is 4°C, the apparent viscosity of pigment increase as the concentration of pigment solution increased, when the concentration is higher than 9%, the viscosity increase rapidly as concentration increased. At higher concentrations, the apparent viscosity of solution decrease as shear rate increased, and it performs as fake plastic flow of non-Newtonian fluid, and while the concentration is <8%, the solution is Newton.fluid.