Fu Shenghui, Liu Zhongfang, Liu Shaopu, Liu Jangtao, Yi Aoer
School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715, PR China.
Anal Chim Acta. 2007 Sep 19;599(2):271-8. doi: 10.1016/j.aca.2007.07.071. Epub 2007 Aug 3.
In pH 2.8-3.8 BR buffer medium, the third generation cephalosporin antibiotics (TGCs) such as ceftazidime (CZD), ceftriaxone (CTRX), cefoperazone (CPZ), and cefotaxime (CFTM) react with palladium(II) (Pd(II)) to form 1:2 yellowish-brown cationic chelates, which further react with 4,5-dibromofluorescein (DBF) to form 1:3 brown ion-association complexes. As a result, not only the spectra of absorption and fluorescence are changed, but also the resonance Rayleigh scattering (RRS) is enhanced greatly and the new RRS spectra are observed. The four TGCs products have similar spectral characteristics and their maximum RRS wavelengths are all located at 291 nm. The quantitative determination ranges and the detection limits of the four TGCs are 0.0065-1.0 microg mL(-1) and 2.0 ng mL(-1) for CZD, 0.0070-1.1 microg mL(-1) and 2.2 ng mL(-1) for CTRX, 0.0090-1.6 microg mL(-1) and 2.7 ng mL(-1) for CPZ, and 0.014-2.2 microg mL(-1) and 4.2 ng mL(-1) for CFTM, respectively. The optimum conditions of the reactions and the effects of foreign substances are investigated, and the composition of ion-association complexes is discussed also. Based on the ion-association reaction, a highly sensitive, simple and rapid method has been proposed to the determination of TGCs.
在pH 2.8 - 3.8的BR缓冲介质中，第三代头孢菌素抗生素（TGCs）如头孢他啶（CZD）、头孢曲松（CTRX）、头孢哌酮（CPZ）和头孢噻肟（CFTM）与钯（II）（Pd（II））反应形成1:2的黄棕色阳离子螯合物，该螯合物再与4,5 - 二溴荧光素（DBF）反应形成1:3的棕色离子缔合物。结果，不仅吸收光谱和荧光光谱发生变化，而且共振瑞利散射（RRS）大大增强，并观察到新的RRS光谱。这四种TGCs产物具有相似的光谱特征，它们的最大RRS波长均位于291 nm处。四种TGCs的定量测定范围和检测限分别为：CZD为0.0065 - 1.0 μg mL⁻¹和2.0 ng mL⁻¹；CTRX为0.0070 - 1.1 μg mL⁻¹和2.2 ng mL⁻¹；CPZ为0.0090 - 1.6 μg mL⁻¹和2.7 ng mL⁻¹；CFTM为0.014 - 2.2 μg mL⁻¹和4.2 ng mL⁻¹。研究了反应的最佳条件和外来物质的影响，还讨论了离子缔合物的组成。基于该离子缔合反应，提出了一种高灵敏度、简便快速的TGCs测定方法。
