同步荧光光谱法测定人体尿液中加替沙星

Determination of Gatifloxacin in Human Urine using Synchronous Fluorimetry

研究了尿样中加替沙星在不同酸碱条件下的荧光特性，发现在中性水溶液中加替沙星的荧光较弱，荧光发射峰位于450nm，尿样背景荧光发射峰位于370nm。由于加替沙星与尿样背景荧光的发射波长部分的重叠，尿样中的加替沙星采用通常的荧光光谱法无法测定。当PH=4．1时，加替沙星的荧光发射显著增强，荧光发射波长由450nm红移至478nm，同时尿样背景荧光反而由中性水溶液中的370nm紫移到355nm。据此建立了一种无需分离直接测定尿样中加替沙星的同步荧光光谱新方法。选择△λ=90nm，在优化条件下，测定加替沙星的线性范围为0．12～3．2μg·mL^-1，检出限为0．04μg·mL^-1。方法用于尿样中加替沙星含量的测定，其回收率为92．6％～96．8％，相对标准偏差为1．6％～2．4％。

The effects of pH on the determination of gatifloxacin （GFLX） in human urine were studied by synchronous fluorimetry. The maximum emission wavelengths of GFLX and the urine blank were at 450 and 370 nm in aqueous solution （pH 7. 0）, respectively. Because the emission spectra of GFLX and fluorescent substance of human urine were overlapped partially, GFLX coudn＇t be determined directly by normal fluorimetric method. However, in pH 4.1 B-R buffer solution, the fluorescence intensity was remarkably enhanced, and the fluorescence emission wavelength of GFLX was red shifted 28 nm from 450 nm to 478 nm, while the emission wavelengths of urine blank suffered a shift from 370 nm to 355 nm. The synchronous spectral peaks of GFLX and the urine blank were at 365 nm and 282 nm, respectively. The synchronous spectrum, maintaining a constant difference of △λ=90 nm between the emission and excitation wavelengths, was selected as optimum to perform the determination. Under the optimal experimental conditions, the linear regression equation of the calibration graph was F=34. 981c ＋5. 058, with a correlation coefficient of 0. 9994. Within the range 0.12-3.2 μg·mL^-1 there existed a good linear relationship between the fluorescence intensity and concentration of GFLX. The detection limit was 0.04 μg·mL^-1. The average recoveries of GFLX was 92.6 %-96.8% and the RSD was 1.6%-2.4%. This method was rapid, simple and highly sensitive for the determination of GFLX in human urine without preseparation.