Preparation of carboxymethyl cellulose picric acid ester and adsorption property for urea and creatinine

Sodium periodate as selective oxidant,oxidized carboxymethylcellulose was prepared from carboxymethyl cellulose under acidic conditions. The carboxyl on C6 of oxidized carboxymethylcellulose was acylated and composite targeted oral adsorbent ester of oxidized carboxymethylcellulose - based picric acid(CMC - PA)was prepared by reaction with it and picric acid. The structure of oxidized CMC - PA was characterized by XRD,FTIR,element analysis and chemical functional determination(alkali fusion method to measure aldehyde content),the results showed that oxidized CMC - PA was prepared. The adsorption property of oxidized CMC - PA to urea and creatinine was studied under simulated biological human body conditions,results showed that adsorption amount reached an equilibrium value after 10h and 6h respectively,aldehyde content was 75. 23%. The saturated adsorption capacity to urea and creatinine were 16. 08mg/g and 2. 10mg/g,respectively. The adsorption isotherms of urea on oxidized CMC - PA fit well with Freundich equation,indicating that the adsorption was mainly chemical adsorption. The Freundich index(1/n)was less than 2,which implied that the adsorption was preferential process.