The Research On Preparation And Performance Of Several Fluorescence Probes And Their Application In Environmental Monitoring

In this thesis, several new fluorescent probes were designed and synthesized by the Schiff base reactions of anthracene or anhydride naphthalene as fluorophore, detecting for metal ions like Fe(III), Cu(II) and Hg(II), and the water content in organic solvents like dioxane and acetone, respectively. The fluorescence performance was surveyed by optimizing the determination conditions and the preliminary application in environmental monitoring was investigated. The main works were as follows:(1) A new fluorescence probe, anthracene formaldehyde derivatives was easily synthesized through the Schiff base reaction of 9-anthraldehyde with 4-aminoacetophenone, which shows good performance in recognition for Fe(III). The fluorescence intensity was apparently changed by addition of different concentration of Fe(III). Hence, one can developed a fluorescence analyzing technology for the determination of trace Fe(III). It was showed that the fluorescence intensity decreased with the increase of the ethanol content, remaining relatively static more than 3.5 ml, under the optimum condition atλex/λem = 402/560 nm and in ethanol-water (3.5/21.5, v/v) solutions. The fluorescence intensity increased with a rise of the value of pH from 2 to 4, keeping fairly constant in the range of pH= 4-8. Therefore, the Tris-HCl buffer solution was used at pH=7.20. In addition, the linear responses for Fe(III) concentration was observed in the range from 6.0×10-9 to 1.0×10-7 mol/L, with the detection limit for Fe(III) of 3.04×10-10 mol/L and the relative standard deviations less than 0.39% .(2) A new fluorescent probe was synthesized by the Schiff base reaction conjugating thiocarbohydrazide into 9-anthraldehyde and its application for detection of trace Cu(II) or Hg(II) in water samples was investigated. The experiment results indicated that the fluorescence intensity of the probe decreased with the increasing concentration of Cu(II) or Hg(II) when it was excited atλex/λem = 402/526 nm in water-acetone (21.5/3.5, v/v) solutions at pH=7.0. The prepared probe presented satisfactory selectivity and the linear response for Cu(II) or Hg(II) concentration was observed in the range from 2.0×10-7 to 2.0×10-5 mol/L with the detection limit for Cu(II) or Hg(II) of 3.14×10-8 mol/L and 8.87×10-8 mol/L, respectively. The developed method was employed for preliminary application in natural water and domestic sewage, with the recoveries in the range of 96.3% to 103.7%.(3) The naphthalimide derivative was synthesized as a fluorescence probe for determining water content in organic solvents. The fluorescence intensity and the wavelength were obviously changed in the presence of various water contents. As demonstrated by fluorescence spectroscopic analysis, various solvents had substantial effects on the fluorescence intensity and the wavelength. The fluorescence spectrum produced the red shift with the increase of the solvent polarity. The pH value of solution affected the fluorescence intensity and the wavelength. The experiment results showed that the probe could be employed to detect water content (0-6%) of dioxane and acetone. The detection limits were 0.046% and 0.184% for dioxane and acetone, respectively. The primary study of the sample was carried by the probe. The results indicated that the prepared probe was successfully employed for determination in real samples, within ideal tolerances.