Studies On The Optical Chemical Membranes For Mercury Ion Based On Organically Modified Sol-gel

The development of fiber optical chemical sensor (FOCS) is an active research area. Compared with tradition laboratory analytical methods, FOCS has many advantages, such as a real time, quick speed, accurate detection and multiparameter/multipoint analysis for environmental pollutant. So it can support reliable data for our environment protection. Using FOCS as determination method, we prepared the optical chemical membranes for detection of mercury ion in water by using organically modified sol-gel.This thesis consists of three chapters: (1) a review; (2) study on the optical chemical membrane for detection of mercury ion by using 5,10,15,20-tetraphenylporphyrin as fluorescence indicator; (3) study on the optical chemical membrane for detection of mercury ion by using 5,10,15,20-tetra(p-sulfonatophenyl)porphyrin as fluorescence indicator.In Chapter one, the laboratory method for determination of mercury ion, the progresses of chemical sensor for detection of mercury ion recently and the introduction of the basic theory, relative merits of sol-gel and its application in optical chemical sensor were involved. At the end of this chapter, the aims of this thesis and the main research contents were also described. In Chapter two, a optical chemical membrane was prepared for detection of mercury ion base on 5,10,15,20-tetraphenylporphyrin by using organically modified sol-gel. By being optimized the compounding ration of predecessor, dopant, catalyst and indicator, the membrane has a good respond to mercury ion in water. The linear response range of membrane was 5.0×10-6~1.0×10-4 mol/L, and the detection limit was 3.6×10-6mol/L. In addition, the stability, reversibility, responsive time of the membrane and the interferences were also studied in detail. The experimental results showed that this membrane has a good stability, good reversibility, good repeatability, short responsive time, long useful life and no interference by salinity.In Chapter three, a optical chemical membrane was prepared for detection of mercury ion base on 5,10,15,20-tetra(p-sulfonatophenyl)porphyrin by using organically modified sol-gel. By being optimized the compounding ration of predecessor, dopant, catalyst, plasticizer and indicator, the membrane has a respond to mercury ion in water. The linear response range of membrane was 1.0×10-5~1.0×10-4mol/L, and the detection limit was 1.5×10-6mol/L. In addition, other capabilities of the membrane were also studied. The experimental results showed that this membrane has a good stability, good reversibility, good repeatability and short responsive time. So this membrane was very suitable for real-time monitoring. At the end of this chapter, a comparison of this membrane with the membrane mentioned in the previous chapter was carried out.In one word, this dissertation introduces the manufacture of optical chemical membranes which has a good respond to mercury ion in water by using organically modified sol-gel, and it also shows a great future in monitoring environmental pollutant by using FOCS based on organically modified sol-gel.