The New Determination Method For Palladium, Silver And Copper In Environment By Fluorescence And Resonance Rayleigh Scattering Technique

Heavy metals have been used widely in the production and live of people, the heavy metals pollution become more and more serious with them into the environment through various ways, it is far beyond the carrying capacity of the environment, the problem of pollution is becoming more and more highlighted. There are many types of heavy metal, and their detection methods are different, the determinations of some common heavy metals including lead, chromium, mercury, cadmium, zinc and aluminum were extensively studied by people, and some of the unusual metal ions was less. Taking palladium, silver and Copper as research objects, we have studied and developed new systems and methods for the determination of the above heavy metal in environment using spectrophotometry, fluorescence and Resonance Rayleigh scattering techniques. The methods are rapid, simple and reliable.1Study on the fluorescence quenching methods for determination of Pd (Ⅱ)(1) The fluorescence quenching of fluoroquinolones by palladium(II) and its analytical applicationIn a weakly acidic or neutral medium, fluoroquinolones (FLQs) such as pefloxacin (PEF), levofloxacin (LEV), lomefloxacin (LOM) and fleroxacin (FLE), have similar fluorescence spectral characteristics. Their fluorescence intensities could be significantly quenched by palladium. In this work, taking Pd(II)-PEF system as an example, the absorption and fluorescence spectral changes were investigated. In addition, the density functional theory (DFT) methods (B3LYP) was performed to optimize those compounds. A Pd (II) molecule bond two PEF molecules to form a square planar chelate with two six-membered rings, and the quenching effect of Pd(II) on PEF fluorescence is a single static quenching event. The detection limits were in the range of1.74-3.42ng/mL using the above four FLQs. Most of metal ions and inorganic anions have no interference. The method was applied to the determination of Pd(II) in environmental water.(2) Synergistic fluorescence quenching of quinolone antibiotics by palladium(II) and sodium dodecyl benzene sulfonate and the analytical applicationIn weakly acidic and neutral media, palladium (II) or sodium dodecyl benzene sulfonate (SDBS) can result in fluorescence quenching of quinolone antibiotics (FLQs) to some different extents. When Pd(II) react with SDBS and FLQs to form ternary complexes, a enhanced fluorescence quenching of FLQs could be observed. This synergistic fluorescence quenching reaction has high sensitivity for Pd(II) and the detection limits could reach to0.13ng.mL-1. Based on this, a rapid, simple and reliable method for determination of Pd(II) in aqueous samples was established. The spectral characteristics of the fluorescence spectra were investigated. The optimum reaction conditions of the method were tested. The interaction between Pd(II), FLQs and SDBS was investigated by absorption spectra, fluorescence spectra, and was calculated by quantum chemical using density function theory B3LYP under polarizable continuum model (PCM). The pefloxacin (PEF) molecules exist as zwitter-ion of HL±reacting with Pd(II) to form2:1plane quadridentate chelates, which further binds two SDBS molecules to form ternary complexes (Pd(II):PEF:SDBS=1:2:2). The ternary complexes resulted in higher fluorescence quenching efficiency and enhanced the sensitivity for determination of Pd(II).(3) Synergistic fluorescence quenching of quinolone antibiotics by palladium(II) and Hexadecyl pyridine bromide and the analytical applicationIn weakly acidic and neutral media, palladium (II) or Hexadecyl pyridine bromide (CPB) can result in fluorescence quenching of quinolone antibiotics (FLQs) to some different extents. When Pd(II) react with CPB and FLQs to form ternary complexes, a enhanced fluorescence quenching of FLQs could be observed. This synergistic fluorescence quenching reaction has high sensitivity for Pd(II) and the detection limits could reach to0.16ng.mL-1. Based on this, a rapid, simple and reliable method for determination of Pd(II) in aqueous samples was established. The spectral characteristics of the fluorescence spectra were investigated. The optimum reaction conditions of the method were tested. The interaction between Pd(II), FLQs and CPB was investigated by absorption spectra, fluorescence spectra, and was calculated by quantum chemical using density function theory B3LYP under polarizable continuum model (PCM). The ternary complexes resulted in higher fluorescence quenching efficiency and enhanced the sensitivity for determination of Pd(II).2Study on new methods for the determination of silver in environment(1) Study on the Interaction between Ag(I) and Erythrosin by Absorption and Resonance Rayleigh Scattering SpectraIn weakly acidic and neutral media, Erythrosin (Ery) can react with Ag(I) to form ion-association complex. As a result, the increase of molecular volum and hydrophobic interface forms are advantageous to enhancement of RRS intensities, and a new RRS spectrum appeared. A sensitive, simple and new method for the determination of Ag(I) by using Ery as the probe has been developed. The detection limits for Ag(I) was0.12ng.mL-1for RRS method. The spectral characteristics of the RRS spectra were investigated. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.(2) Study on the Interaction between Ag(I) and Eosin Y by Absorption and fluorescence SpectraIn weakly acidic and neutral media, Eosin Y (EY) can react with Ag(I) to form ion-association complex. As a result, the complex could quench the fluorescence of EY. Based on change of absorption spectra, increase of temperature resulting in fluorescence quenching decrease and high apparent quenching constants, these indicated the quenching effect was a static quenching event. We developed a new method for the determination of Ag(I), the detection limits was0.24ng.mL-1. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.3Study on new methods for the determination of copper in environment(1) Study on the interaction Cu(I) and Erythrosin by Absorption and Resonance Rayleigh Scattering SpectraIn weakly acidic and neutral media, Cu(II) is redox to Cu(I) by vitamin C, Erythrosin (Ery) can react with Cu(I) to form ion-association complex. As a result, the increase of molecular volum and hydrophobic interface forms are advantageous to enhancement of RRS intensities, and a new RRS spectrum appeared. A sensitive, simple and new method for the determination of Cu(I) by using Ery as the probe has been developed. The detection limits for Cu(II) was0.58ng.mL-1for RRS method. The spectral characteristics of the RRS spectra were investigated. The optimum reaction conditions of the method were tested. The method was applied to the determination of Ag(I) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.(2) Study on the Interaction Cu(I) and Eosin Y by Absorption and fluorescence SpectraIn weakly acidic and neutral media, Cu(II) is redox to Cu(I) by vitamin C, Eosin Y (EY) can react with Cu(I) to form ion-association complex. As a result, the complex could quench the fluorescence of EY. Based on change of absorption spectra, increase of temperature resulting in fluorescence quenching decrease and high apparent quenching constants, these indicated the quenching effect was a static quenching event. We developed a new method for the determination of Cu(II), the detection limits was3.7ng.mL-1. The optimum reaction conditions of the method were tested. The method was applied to the determination of Cu(II) in environmental water, and the result was fine. In addition, the reaction mechanism was discussed.