Preparation Of Fumonisins Absorbent And Evaluation Of Adsorptive Efficiency To FB₁in Vitro

In this study,2kinds of bentonite screened out by the ion exchanging capacity analysis were selected as matrix, a kind of natural polysaccharide with polar groups as modifier,21kinds of modified samples are prepared by changing the ratio of matrix and modifier.modifier solution solvent, reaction time etc. The modification effect of betonies by polysaccharide in various reaction conditions was determined through the analysis of the X-ray powder diffraction pattern and the modifier content of the modified samples. The adsorption rate of FB1in vitro by the samples mentioned above was evaluated in the pure solvent and simulated animal gastrointestinal tract environment conditions. By synthesizing the physicochemical characterization of the results, analyzing factors affecting the modification effect,we screened the optimized process and parameters. This experiment also established evaluation method of adsorption efficiency of modified adsorbent for FB1under the conditions of a pure solution in vitro.Exp.1:The feasibility verification of the FL method to determination of FB1in aqueous media。In this test,the self-designed fluorescence method used a to to evaluate the modified samples adsorption efficiency on FB1, and the evaluation results were checked by HPLC.FB1show good linearity in the range of0.5μg mL-1-10μg mL-1and correlation coefficient were0.9987,the rate of recovery was80.18%-100.34%, the intra-day coefficients of variation was4.88%-5.40%, daytime variation coefficient is4.82%-10.24%. But the results measured by fluorescence photometer on evaluation of modified sample adsorption efficiency of FB1varied widely with the results measured by HPLC.so the fluorescence photometer can not be used to evaluate the efficiency of the adsorption of FB1by modified samples. Exp2:Preparation of the modified samples and analysis of modification effect.According to the quantity of ion exchange,2out of5kinds of bentonite were selected as matrix and modified respectively. Using the single-factor experimental design during modification process, this experiment examined effects of a variety of modified factors such as matrix of different ion exchange capacity (bentonite A:CEC=140; bentonite B:CEC=85), the proportion of modifier with the matrix(0.2:1,0.8:1,1.6:1,3.2:1), solvent of modifier solution (1%acetic acid solution,0.1mol·L-1hydrochloric acid solution), the way bentonite added to the modifier solution (soil suspension, dry soil) and the reaction time (1,2,4,8,16,24,32h) on the amount of polysaccharide in the modified samples. The analysis of the modifier amount and the analysis of X-ray powder diffraction showed that: under the condition of the modification ratio of3.2:1, bentonite A mixed with0.1mol·L-1hydrochloric acid solution modifier in the form of a suspension, oscillating reaction of8h under the condition of60℃, the per gram modifier content of modified samples was up to128mg, the lamellar spacing of bentonite Increased from14.2A to15.1A after modified, indicating that organics successfully intercalated into the interlayer of bentonite crystal.Exp3:Evaluation of adsorptive efficiency to FB1by modified samples in vitro1) Evaluation of adsorptive efficiency to FB1in methyl cyanide water pure solution in vitro and simulated gastrointestinal environment. In the pure solution environment in vitro, when the density of FB1was4μg·L-1and the matrix or modified sample was1mg·mL-1, the adsorptive rate to FB1of unmodified bentonite A was18.5±6.4%, the adsorptive rate to FB1of all the modified samples was fine, and it was much improved as compared to unmodified bentonite. The adsorptive rate to FB1of the best one in23kinds of modified samples reached100%. In simulated gastrointestinal tract environment experiment, When the density of FB1in the gastric environment and small intestine environment was150ng·mL-1, matrix or modified samples density was1mg·mL-1, compared to pure solution environment in vitro, there was a poor adsorptive rate to FB1.In gastric environment, the adsorptive rate to FB1reached up to63.3±7%.In small intestinal fluid the best adsorptive rate to FB1was only42.7±20.5%.2) A series of modified adsorbent samples were prepared by single factor experiment design, after analyzing the modification effect and analyzing the adsorptive rate to FB1in vitro, the optimization of the process parameters were determination:1%polysaccharide solution (0.1M hydrochloric acid as the solvent, pH=4.9) was batch slowly into2%bentonite A suspension, high-speed stirring,then constant temperature water bath shaker reaction about8h in60℃. The proportion of polysaccharides and bentonite was3.2:1.