Department of Chemistry, Kyungpook National University, Taegu, 702-701, Korea.
Luminescence. 2011 Nov-Dec;26(6):768-73. doi: 10.1002/bio.1311. Epub 2011 May 24.
A sensitive fluorescence (FL) technique is proposed for the determination of levofloxacin (LVX). The method is based on the fact that the weak FL signal of the Tb(III)-LVX system is strongly enhanced in the presence of gold nanoparticles. Gold nanoparticles were prepared by the citrate reduction of HAuCl(4) and characterized by transmission electron microscopy (TEM). Levofloxacin and Tb(III) ion form a fluorescence complex in aqueous solution, and its maximum emission wavelength was found at 545 nm. Optimal conditions for the formation of the levofloxacin-Tb(III) complexes were studied. Levofloxacin was detected by measuring the FL intensity, which increases linearly with the concentration of LVX in the range 6.2 × 10(-10)-2.6 × 10(-8) mol/L. Recovery of the target analytes was > 96% with good quality parameters: linearity (r(2) > 0.996), limit of detection (LOD) and limit of quantification (LOQ) values 2.1 × 10(-10) mol/L and 7.2 × 10(-10) mol/L, and run-to-run and day-to-day precisions with relative standard deviations (RSDs) around 3%. Thus, the proposed method can be successfully applied to the routine determination of levofloxacin in pharmaceutical preparations.
提出了一种用于测定左氧氟沙星（LVX）的灵敏荧光（FL）技术。该方法基于以下事实：在存在金纳米粒子的情况下，Tb（III）-LVX 体系的弱 FL 信号得到了强烈增强。金纳米粒子是通过 HAuCl4 的柠檬酸盐还原制备的，并通过透射电子显微镜（TEM）进行了表征。左氧氟沙星和 Tb（III）离子在水溶液中形成荧光络合物，其最大发射波长为 545nm。研究了形成左氧氟沙星-Tb（III）络合物的最佳条件。通过测量 FL 强度来检测左氧氟沙星，其强度随 LVX 浓度在 6.2×10(-10)-2.6×10(-8)mol/L 范围内呈线性增加。目标分析物的回收率>96%，具有良好的质量参数：线性（r²>0.996）、检测限（LOD）和定量限（LOQ）值分别为 2.1×10(-10)mol/L 和 7.2×10(-10)mol/L，以及运行间和日间精密度，相对标准偏差（RSD）约为 3%。因此，该方法可成功应用于药物制剂中左氧氟沙星的常规测定。
