Miao Yanhong, Hou Faju, Jiang Chongqiu
Department of Chemistry, Shandong Normal University, Jinan 250014, China.
Anal Sci. 2005 Oct;21(10):1207-11. doi: 10.2116/analsci.21.1207.
A new spectrofluorometric method was developed for the determination of trace amounts of heparin (Hep). Using ciprofloxacin (CIP)-terbium (Tb3+) as a fluorescent probe, in a buffer solution of pH 7.20, Hep can remarkably enhance the fluorescence intensity of the CIP-Tb3+ complex at lambda = 545 nm; also, the enhanced fluorescence intensity the Tb3+ ion is proportional to the concentration of Hep. The optimum conditions for the determination of Hep were also investigated. The dynamic range for the determination of Hep is 0.1 - 1.2 microg ml(-1) with a detection limit of 6.89 ng ml(-1). This method is simple, practical and relatively free of interference from coexisting substances, and can be successfully applied to assess Hep in biological samples. By the Rosenthanl graphic method, the association constant and binding numbers of heparin with the probe are 2.44 x 10(5) l mol(-1) and 19.7. Moreover, the enhancement mechanisms of the fluorescence intensity in the CIP-Tb3+ system and the CIP-Tb3+-Hep system have also been considered.
开发了一种新的荧光分光光度法用于测定痕量肝素(Hep)。以环丙沙星(CIP)-铽(Tb3+)作为荧光探针,在pH 7.20的缓冲溶液中,肝素能显著增强CIP-Tb3+络合物在λ = 545 nm处的荧光强度;此外,Tb3+离子增强后的荧光强度与肝素浓度成正比。还研究了测定肝素的最佳条件。测定肝素的动态范围为0.1 - 1.2 μg ml(-1),检测限为6.89 ng ml(-1)。该方法简单、实用,相对不受共存物质干扰,可成功应用于生物样品中肝素的评估。通过Rosenthanl图解法,肝素与探针的缔合常数和结合数分别为2.44 x 10(5) l mol(-1)和19.7。此外,还考虑了CIP-Tb3+体系和CIP-Tb3+-Hep体系中荧光强度增强的机制。