Preparation And Study Of Adsorption Properties In Organics Of Chemically Modified Stationary Phase

In the dissertation, new methods for preparation and application of fixation phaseare studied, which is modified by electrochemical and surface chemical.5-sulfosalicylicacid modified stationary phase using cyclic voltammetry and β-cyclodextrin modifiedstationary phase using surface chemical are producted. These modified stationaryphases had been applied successfully to absorb phenol and aniline in water samples. Theadsorption effect of the chemically modified stationary phase are both obviouslyimproved than that without chemically modified.The preparation of chemically modified stationary phase is compound with liquidparaffin, graphite and activated carbon by a certain percentage, and pressed intopolyethylene tube. After the handle with the stationary phase in the30%hydrogenperoxide, then5-sulfosalicylic acid and PBS (pH=7.4) were modified onto the surfaceby cyclic voltammetry, and then letting5-sulfosalicylic acid bonding on the stationaryphase tightly. And than we studied the static adsorption properties of5-sulfosalicylicacid chemical modified fixation phase on aniline. it shows that after being modified by5-sulfosalicylic acid modification, the chemically modified stationary phase’s ability ofabsorption aniline improves a lot, and absorption rate rises from20%to50%at2.67μg/mL aniline. In static absorption, the absorption rate is connected to such factorsas temperature or the oscillation time. The isothermal adsorption curve of chemicallymodified electrode for aniline is better fits Freundlich isothermal equation, so thechemically modified electrode’s absorption of anilne is the physical endothermicprocedure.The preparation of chemically modified stationary phase which modified byβ-cyclodextrin is studied. Mixed with a sercent amount of graphite and activated carbon,adding a certain volume of cyclodextrin, soaked for a certan time, and then dried at80℃. At last added in liquid paraffin, and full mixing, and pressed into polyethylene tube. This modified stationary phase is applied to absorb phenol and aniline in water.Results show that after being modified by β-cyclodextrin modification, the chemicallymodified stationary phase’s ability of absorption phenol and aniline improves a lot, andabsorption rate rises from20%to72%at6μg/mL aniline, and absorption rate rises from20%to60%at1.6μg/mL phenol. Within the scope of the study, The isothermaladsorption curve of chemically modified stationary phase for aniline is better fitsFreundlich isothermal equation, and phenol is better fits Langmuir isothermal equation.The absorption is spontaneous endothermic reaction, meets the physical adsorptionprocess controled by pseudo-second kinetics.