| AbstractMany people have noticed the research of the ammonian compounds that exist in water all the tune since the environmental water quality is going to overnutrition. In the procedure of the environmental monitoring ,the determination of the ammonian compounds especially the concentration of ammonia in the drinking water, surface water N food, workshop and clinic is very important. In order to meet the demand of the environmental science up-to-date, it is a task now to monitor the environment by utilizing the advanced technology to gain the in-situ, instantaneous, highly sensitive, and highly stable analytical characters' information. So we tried to establish a real time, rapid, accurate method to motor the concentration of ammonian compounds in water.The paper consists two chapters. In the first chapter, we emphasized on studying the porous optics probe for ammonia. And in the second chapter, we investigated the porous probe for pH.In the first chapter, there are three parts. The first part is the review of the literature. We summarized a variety of methods of measuring the concentration of ammonia, particularly emphasizing on ammonia sensor especially the research and development of optics and optics fiber sensor for ammonia.In the second part, we studied the plastic porous probe for ammonia measurement, which was made by Methyl methylacrylate. We selected Methyl methylacryte(MMA) as the monomer, Diethylene glycol dimethacrylate(DGDM) as cross-linking agent and toluene as the inert solvent. The probe was prepared by a copolymerization technique. At the same time, we entrapped the pH sensitive agent in the probe. When the probe was exposed to dissolved ammonia, ammonia would enter into the probe through the pore and react with the indictor, and then the fluorescence intensity of the indictor would increase. So we could measure the ammonia by the intensity changes. In this paper, effects of ammonia and pH on response character of the probe with different interpolymerization materials' proportion, different porosity, and different amount of indictor were investigated. The results showed that :(D the use level of the cross-linking agent had a great effect on the character of the probe; The volume was too small, it would result in producingimpermanent pores; and the volume was too large, the result showed that the structure of the probe was tight, and the amount of pores were less, it would influenced the probe's sensibility. (2) the use level of inert solvent was important too: The volume was larger, the losing of the indicator was more severe; the volume was smaller, the amount of pores were less; either went against improving the sensibility of the probe. (3) the amount of the indicator added in the probe would have an effect on the probe's sensibility. ?the changes of the cross-linking agent and inert solvent would not change the probe's hydrophobicity. So in our investigate, the optimum cross-linking level was 70%, the optimum volume of inert solvent was 0.05ml, and the amount of indicator added was 5. OX 10"8mol.Under the condition of optimum compounding ration, the linear respond range of the probe was 2.0X 10"4mol f !~9.1 X 10~3mol -L~l. The stability , reversibility of the probe and effects of the interferent and salinity were also studied.In the third part, we introduced an ammonia porous plastics probe which was made by styrene. We selected styrene as monomer, Diethylene glycol dimethacrylate as cross-linking agent. The copolymerization technique was used in preparing the probe. The pH fluorescent indicator was immobilized in the probe as the sensitive element. In this part, we used the same research method as the second part. Effects of pH and ammonia on response character of probe with different interpolymerization materials' proportion and with different porosity were investigated. The result showed that the linear respond range of this porous plastics sensitive probe was 2.0X 10~4mol ?L"'~9.1 X 10~3mol ?IT1. The stability ^ reversibility of the probe and effects of the inte... |
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