Research On Detection And Application Of Heavy Metal Ions In The Water

Water is one of the basic material basis for human life, which quality directly affects the social and economic sustainable and steady development. Nowadays, with the rapid development of urbanization, the problem of water pollution is becoming more and more serious, especially the pollution of heavy metal. The research on detection methods of heavy metal ions has caused wide attention of many researchers. The fluorescent probe analysis with high sensitivity, easy-to-operate, less dosage of samples, and the advantages of low cost, fast and convenient, therefore, it has become the important tool of the fluorescence analysis method. In this thesis three kinds of probes were synthesized, characterized and applicated, in order to dectect the iron ion, copper ion and mercury ion in water samples. Specific content as follows:(1) A new compound(fluorescent probe P1) based on BOPIDY was synthesized, according to the established method of iron ion detection in the water. To explore the fluorescence spectrum properties of the probe, investigate the effect of time and other interfering ions. The results showed that the probe had high selectivity for iron ion, and it was not affected by the interference of common metal ions. When Fe3+ concentration was within 0~1 μmol/L, there existed positive linear concentration between the fluorescence intensity and its concentration, the regression equation was: y=-6226400x+8097400(R2 = 0.9972). What′s more, the probe was used to the actual determination of trace iron in water samples, the recovery rate was between 87.32%~107.76%, with a good practicability.(2) A new compound of high sensitive selective colorimetric fluorescence dual channel fluorescence molecular probe(P2) was synthesized, through the established method of copper ion detection in the water. The experiment studied fluorescence spectrum properties, reaction time of the probe. And the influence factors of concentration, interference ions. The fluorescence probe presented specific selectivity and high sensitivity for copper ion in acetonitrile/water solution. The fluorescence intensity had good linear relationship with its concentration, the regression equation was y=0.018+0.010x(R2=0.996), meanwhile the detection limit was 0.06 μmol/L. The probe was applied to the actual determination of trace copper in water samples, the recovery rate was between 80.05%~98.65%, with high reliability and good practicability.(3) A coumarin compounds probe(P3) was synthesized based on the extablished method of mercury ion in the water, and examine the feasibility of this method. When ethanol: water = 1:1 system(pH = 7.4, PBS buffer), the probe can be able to realize the detection of mercury ion, the detection limit was 0.07 μmol/L. When the concentration of mercury ion was in the range of 0~4 μmol/L, the concentration of mercury ion and fluorescence intensity had a good linear relationship, the regression equation was: y=107305x+99254(R2=0.9875). The probe was not affected by the co-existing ions, such as K+, Na+, Mg2+, Zn2+, Ni2+, Cr3+, Cd2+, Pb2+, Cu2+, and it has very good selectivity for mercury. The probe is used for the actual determination of mercury in samples, the rate of recovery was between 82.02%~108.26%, showing a good practicability.