洛美沙星的铕离子荧光探针时间分辨荧光法测定

Determination of Lomefloxacin Using Europium Ion as Fluorescent Probe by Time-resolved Fluorometry

采用时间分辨荧光法，以铕离子为荧光探针，依据Eu3＋La3＋-LMX—SDS稀土共发光体系，建立了测定洛美沙星（LMX）含量的新方法。研究了配合物的紫外及荧光光谱，分析了配合物的发光机理，考察了溶液pH值、缓冲溶液种类及反应试剂加入量对配合物荧光强度的影响。在优化的实验条件下，配合物荧光强度和洛美沙星浓度呈线性关系，相关系数为0．9990，线性范围为5．0×10-7-1．0×10～mol／L。方法的检出限为6．8×10mol／L，对5．0×10-6mol／L的洛美沙星溶液测定11次，RSD为0，6％。将该方法用于尿液中洛美沙星含量的测定，回收率为94％～104％。

A time-resolved fluorometric method for the determination of lomefloxacin（LMX） based on columinescence effect of Eu3＋ - La3 ＋ - LMX - SDS （ sodium dodecyl sulfate） system was developed using europium ion as fluorescent probe. UV and fluorescence spectra of the complexes were studied and the luminescence mechanism was discussed. In the complex of Eu3＋ - LMX - SDS, LMX absorbs UV light at 283 nm and transfers the energy to Eu3＋ , that is, intramolecular energy transfer occurring. In pH 6. 8 hexamethylene tetramine （HMTA） - HC1 buffer, Eu3 ＋ - LMX - SDS complex gives characteristic emission of Eu3＋ at 616 nm, and the emission intensity can be enhanced greatly in the presence of La3＋. The experimental conditions, including pH value and type of buffer, con- centration of reaction reagents were investigated. The best conditions were obtained by using 3.0 × 10 -6 mol/L Eu3 ＋ , 2. 5× 10 -4 mol/L SDS and 1.0 × 10-5 mol/L La3 ＋ in pH 6.8 buffer. Under the optimum conditions, a good linearity was obtained between the fluorescence intensity and LMX con- centration in the range of 5.0 × 10 -7 - 1.0 × 10 -5 mol/L. The linear regression equation was AI = -37.08 ＋7.435c（ × 10-7 tool/L） with a correlation coefficient of 0. 999 0. The detection limit was 6.8 × 10 8 mol/L and RSD for 5.0 × 10-6 mol/L LMX solution（n = 11 ） was 0. 6% . Effect of some coexisted ions on fluorescence intensity of the system was also investigated. The method was applied in the determination of LMX in urine samples with recoveries between 94% and 104%.