Study On The Determination Of Sarafloxacin And Human Serum Albumin Based On Terbium Fluorescent Complexes

Rare-earth fluorescent complexes have the advantages of low excitation energy, high fluorescence emission intensity, narrow half-peak width of emission peak, large Stokes shift and long fluorescence lifetime, which has attracted much attention. Sarafloxacin (SRFX) is one of fluoroquinolones used to control poultry colibacillosis, but irrational use of the drug for a long time will cause residual of SRFX in vivo animal. Having this kind of animal derived food can cause great harm to human healthy. Human serum albumin (HSA) is a kind of protein in plasma. In the clinical medical diagnosis, the determination of HSA can provide the basis for the clinical diagnosis, curative effect observation and the judgment after cure. Therefore, the establishments of sensitive, fast and simple determination methods for SRFX and HSA have great significance.SRFX could form the coordination complex with Tb3+, the fluorescence intensity of Tb3+is increased by3.3times in the presence of sodium lauryl sulfate (SDS) and boric acid. Based on this phenomenon, a fluorescence method was developed for the determination of SRFX. At the optimum conditions, a good linearity between the fluorescence intensity of the system and the concentration of SRFX in the range of0.100～1.80×103ng/mL was obtained. The linear regression equation was△I=26.77c+21.60(the unit of c is ng/mL) with a correlation coefficient of0.9994and the detection limit was0.02ng/mL. The method has been applied to the determination of SRFX in milk samples with RSD between3.1%and4.7%and recoveries in the range of95.5～101%. The results of the experiment showed that the method was accurate and reliable. Studies on collaborative sensitized effect of sodium lauryl sulfate and boric acid were discussed in this paper.The fluorescence intensity of Tb3+-SRFX could be enhanced by HSA. Based on this phenomenon, a simple and sensitive fluorescence method for the determination of HSA has been developed. At the optimum conditions,△I is proportional to the concentration of HSA in the range of0.500～90.0mg/L. The linear regression equation was AI=41.21c+5.15(the unit of c is mg/L) with a correlation coefficient of0.9990and the detection limit was0.13mg/L. The method has been applied to the determination of HSA in normal human serum samples with RSD of1.8%and recoveries in the range of99.2～99.6%. The results of the experiment showed that the method was accurate and reliable.