| Resonance Rayleigh scattering(RRS)and Resonance nonlinear scattering(RNLS)are new analytical technology developed in recent ten years.For their excellence of high sensitivity,cheap instrument,simple operation and rapid analysis speed,these methods bring to more attention and have been studied widely and applied more and more.At present,these technologies are mainly used to the study of biological macromolecules such as nucleic acids,proteins and saccharide.Resonance Rayleigh scattering and Resonance nonlinear scattering can also be used to determination of some pharmaceuticals.But there are not seen literatures reported to determinate cephalosporin antibiotics by these technologies.Furthermore,in this work,ceftazidime,ceftriaxone,cefoperazone,and cefotaxime are as examples to study the interactions among cephalosporin antibiotics,metal ions and organic ions as such dye,surfactant by RRS and RNLS techniques.Besides,the spectral characteristics,optimum reaction conditions,influencing factors,reaction mechanisms,and their analytical applications have been studied.1.Study on the resonance Rayleigh scattering spectra of the interactions of palladium(â…¡)-cephalosporins chelates with 4,5-dibromofluorescein and their analytical applicationsIn pH 2.8-3.8 BR buffer medium,the third generation cephalosporin antibiotics(TGCs)such as ceftazidime(CZD),ceftriaxone(CTRX),cefoperazone(CPZ),and cefotaxime(CFTM)react with palladium(â…¡)(Pd(â…¡))to form 1:2 yellowish-brown cationic chelates,which further react with 4, 5-dibromofluorescein(DBF)to form 1:3 brown ion-association complexes.As a result,not only the spectra of absorption and fluorescence are changed,but also the resonance Rayleigh scattering(RRS) is enhanced greatly and the new RRS spectra are observed.The four TGCs products have similar spectral characteristics and their maximum RRS wavelengths are all located at 291 nm.The quantitative determination ranges and the detection limits of the four TGCs are 0.0065-1.0μg mL-1 and 2.0 ng mL-1for CZD,0.0070-1.1μg mL-1and 2.2 ng mL-1for CTRX,0.0090-1.6μg mL-1and 2.7 ng mL-1for CPZ,and 0.014-2.2μg mL-1and 4.2 ng mL-1for CFTM,respectively.The optimum conditions of the reactions and the effects of foreign substances are investigated,and the composition of ion-association complexes is discussed also.Based on the ion-association reaction,a highly sensitive,simple and rapid method has been proposed to the determination of TGCs.2.Study on the resonance Rayleigh scattering,second-order scattering and frequency doubling scattering spectra of the interactions of palladium(â…¡)-ceftriaxone chelate with anionic surfactants and their analytical applicationsIn pH1.8-2.9 Britton-Robinson(BR)buffer medium,ceftriaxone(CTRX)can react with palladium(â…¡)(Pd(â…¡))to form 1:2 cationic chelate,which can further react with anionic surfactants (AS)such as sodium lauryl sulfonate(SLS),sodium dodecyl sulfate(SDS)and sodium dodecylbenzene sulfonate(SDBS)to form 1:3 ion-association complexes.As a result,the resonance Rayleigh scattering(RRS),second-order scattering(SOS)and frequency doubling scattering(FDS) were enhanced greatly.The maximum RRS,SOS and FDS wavelengths of three ion-association complexes were located at 335 nm,560 nmand 390 nm,respectively.The increments of scattering intensity(Î”â… )were directly proportional to the concentrations of CTRX in certain ranges.The detection limits(3σ)of CTRX for SLS,SDBS and SDS systems were 1.8 ng ml-1,2.3 ng ml-1 and 2.3 ng ml-1(RRS method),4.9 ng m1-1,7.4 ng m1-1and 4.7 ng ml-1(SOS method)and 6.8 ng m1-1, 7.3 ng m1-1and 9.1 ng ml-1(FDS method),separately.The sensitivity of RRS method was higher than those of SOS and FDS methods.The optimum conditions of RRS tnethod and the influence factors were investigated,and the composition of ion-association complexes and the reaction mechanism were discussed also.The effects of foreign substances were tested and it showed that the method has a good selectivity.Based on the ion-association reaction,the sensitive,simple and rapid methods for the determination of CTRX have been developed.3.The absorption,fluorescence and resonance Rayleigh scattering spectra of Cu (â…¡)-seftriaxone-erythrosin ion-association complex system and their analytical applicationsIn pH 4.4～5.1 Britton-Robinson(BR)buffer solution,ceftriaxone sodium(CTRX)reacts with Cu(â…¡)and Erythrosin(Ery)to form 1:2:3 ion-association complex,it results in the change of absorption spectra,the quenching of fluorescence and the great enhancement of Resonance Rayleigh Scattering(RRS),and the new RRS spectra appear.The maximum RRS wavelength is located at 329 nm.The increment of absorption,the quenching of fluorescence and the enhancement of RRS are all proportional to the CTRX concentration in a certain range.The quantitative determination ranges and the detection limits of the three methods for CTRX are 4.4x10-7～4.0×10-6g mL-1and 1.3×10-7 g mL-1(spectrophotometry),2.4×10-7～1.5×10-6g mL-1and 7.2×10-8g mL-1(fluorimetry),and 2.9×10-8～2.0×10-6g mL-1and 8.8×10-9g mL-1(RRS),respectively.The optimum condition of the experiment was investigated.The composition of ion-association complex and the mechanism of reaction were discussed.Besides,the effects of some co-existing substances determination of CTRX by RRS were investigated.The RRS method has not only high sensitivity but also good selectivity.It can be applied to determination of CTRX in serum and urine samples with satisfactory results.4.Study on the resonance Rayleigh scattering spectra of the interactions of HgCl2-cefotaxime anionic chelate with basic triphenylmethane dye and their analytical applicationsIn pH 5.3～6.8 Britton-Robinson(BR)buffer medium,Cefotaxime sodium(CFTM)can react with HgCl2 to form 1:1 anionic chelate,which can further react with basic triphenylmethane dye such as crystal violet,methyl violet,ethyl violet,brilliant green,iodine green,methyl green and malachite green to form ternary ion-association complexes.As a result,the resonance Rayleigh scattering(RRS)was enhanced greatly.The maximum RRS wavelengths of three ion-association complexes were located at 367 nm,367 nm,340 nm,367 nm,340nm,340 nm and 340 nn, respectively.The increments of scattering intensity(â–³I)were directly proportional to the concentrations of CFTM in certain ranges.The linear ranges and the detection limits(3σ)of CFTM for seven systems were 0.0089～3.5μg mL-1and 2.7 ng ml-1(crystal violet),0.0092～3.5μg mL-1 and 2.8 ng mL-1(methyl violet),0.013～3.5μg mL-1and 4.0 ng ml-1(ethyl violet),0.010～3.5μg mL-1and 3.1 ng mL-1(brilliant green),0.0 11～3.5μg mL-1and 3.4 ng mL-1(iodine green),0.012～4.0μg mL-1and 3.5 ng mL-1(methyl green),and 0.016～3.5μg mL-1and 4.7 ng mL-1(malachite green), separately.The sensitivity of crystal violet system was higher than those of other six systems.The optimum conditions and the influence factors were investigated,and the composition of ion-association complexes and the reaction mechanism were discussed also.The effects of foreign substances were tested and it showed that the method has a good selectivity.Based on HgCl2 and basic triphenylmethane dye,the sensitive,simple and rapid method for the determination of trace CTRX has been developed.5.Study on the resonance Rayleigh scattering,second-order scattering and frequency doubling scattering spectra of the interaction of Ce(â…£)with cefoperazone and their analytical applications In pH 3.5～5.6 HAc-NaAc buffer medium,cefoperazone(CPZ)can be oxidized by Ce(â…£), and the oxidation can further react with Ce(â…¢)to form a complex.As a result,not only the spectra of fluorescence(FL)is changed,but also the resonance Rayleigh scattering(RRS),second-order scattering(SOS)and frequency doubling scattering(FDS)are enhanced greatly.The maximum excitation(λex)and emission(λem)wavelengths are at 256 nm and 349 nm,respectively.The maximum RRS,SOS and FDS wavelengths are located at 312 nm,550 nm and 390 nm,respectively. The increments of fluorescence intensity(ΔF)and scattering intensity(Δ1)were directly proportional to the concentrations of CPZ in certain ranges.The linear ranges and the detection limits(3σ)of CPZ for the proposed methods were 0.22-2.5μg mL-1and 6.5 ng mL-1(FL), 0.0071-2.5μg mL-1and 2.1 ng mL-1(RRS),0.018-2.5μg mL-1and 5.4 ng mL-1(SOS),and 0.022-4.5μg mL-1and 6.6 ng mL-1(FDS),separately.The sensitivity of RRS method is higher than those of FL,SOS and FDS methods.The optimum conditions of RRS method and the influence factors are investigated.The effects of foreign substances are tested and it showed that the method has a good selectivity.Based on Ce(â…£),the sensitive,simple and rapid methods for the determination of CPZ have been developed.It can be applied to determination of CPZ in serum and urine samples with satisfactory results. |
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