Study On The Determination Of Clinafloxacin And Piroxicam Based On Europium Fluorescent Complexes

Rare earth complexes have excellent optical properties,such as large Stokes shift,long fluorescence lifetime and linear emission spectrum,which have been used in chemical detection,biomarking and luminescence imaging.Clinaofloxacin(CLI)is one of the fourth generation of fluoroquinolones,which is often used to treat lung and surgical infection in animals.Piroxicam(PX)is a long-acting non-steroidal anti-inflammatory drug that can be used to treat diseases such as rheumatoid arthritis,rheumatoid arthritis and acute musculoskeletal disorders.In clinical medicine,the improper use of drugs can cause the residues of drugs in the body,which is harmful to human health.Therefore,it is necessary to establish a sensitive,accurate,simple and rapid analysis method of CLI and PX.Time-resolved fluorescence is an analytical method based on the different fluorescence lifetimes of luminescent materials,compared with common fluorescence methods,time-resolved fluorescence analysis can effectively eliminate the interference of background fluorescent signals,thus providing higher sensitivity and accuracy.This experiment established a time-resolved fluorescence analysis method for the determination of two drug molecules,CLI and PX.Using Eu3+ as a central ion,it combines with the CLI to form a binary complex.Fluorescence-inert La3+ and sodium dodecylbenzenesulfonate(SDBS)were added.Due to the co-luminescence effect of La3+ and the sensitizing effect of the surfactant,the fluorescence intensity of the complex increases,and a time-resolved fluorescence method for determining CLI is established accordingly.According to the co-luminescence effect of La3+ and the sensitizing effect of the surfactant,the fluorescence intensity of the complex is increased to establish a time-resolved fluorescence method for determining CLI.The experimental conditions of the reaction were optimized.Under the optimal experimental conditions,when the CLI concentration was between 5.00×10-7～1.40×10-5 mol/L,the CLI concentration had a good linear relationship with the fluorescence intensity of the system.The linear equation isΔI=-6.79+68.04c(×10-6 mol/L),the correlation coefficient is R=0.9989,and the detection limit of the method is 6.4×10-8 mol/L.The method was applied to the determination of CLI in milk,and the recovery rate was between 98.6%and 109%.The mechanism of fluorescence sensitization of SDBS and La3+ complexes was discussed in the paper.Under the appropriate reaction conditions,Eu3+reacts with PX and phenanthroline(phen)to form a ternary complex.With the addition of the surfactant Tween-80(TW-80),the fluorescence intensity of the Eu-PX-phen complex was greatly enhanced,and a time-resolved fluorescence method for the determination of PX was established.The optimum measurement conditions were determined by optimizing the reaction conditions of the complex by a single factor test and an orthogonal test.When the PX concentration is between 1.00×10-7～6.00×10-6 mol/L,the concentration of PX has a good linear relationship with the fluorescence intensity of the system.The linear equation is ΔI=-0.11+13.68c(×10-7 mol/L),linear correlation coefficient R=0.9997,the detection limit of the method is 3.2×10-8 mol/L.The content of PX in serum was determined by this method,and the recovery rate was between 95%and 102%.The results were satisfactory.The mechanism of fluorescence sensitization of phen and TW-80 complexes was discussed in the paper.