在pH=9.4的NH4Cl-NH3·H2O的缓冲溶液条件下,强力霉素能与铕(Ⅲ)生成二元络合物并发射出铕(Ⅲ)位于612 nm处的特征荧光,加入2,6-二乙氧基-β-环糊精后,体系的荧光强度显著增强,且增强的荧光强度与强力霉素的浓度呈线性关系,据此建立了荧光分光光度法测量强力霉素的方法。在最佳实验条件下,测量的线性范围和检出限分别为6.2×10^-8-1.3×10^-5mol/L和1.4×10^-8mol/L。本方法曾用于血样和尿样中强力霉素的测定。本研究讨论了荧光增强的机理。
A simple sensitive spectrofluorimetric method was developed for the determination of doxycycline (DC). Ethyl substituted β-eyclodextrin can enhance remarkably the fluorescence intensity of europium ( m ) - doxycycline complex at λem = 612 nm. The experiment results showed that the enhanced fluorescence intensity was in proportion to the concentration of doxycycline under the optimum experiment condition. The linear range and the limit of detection were 6.2×10^-8 - 1.3 ×10^-5mol/L and 1.4 ×10^-8mol/L, respectively. The developed method has been used for the determination of doxyeyeline in samples of urine and serum. The enhancement of the fluorescence at λcm = 612 nm of Eu^3+ ion is because of the formation of inclusion complex 2,6-diethyl-O-cyclodextrin ( DE ) -β-C D-DC-Eu^3 +.