Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing, People's Republic of China.
Anal Biochem. 2012 Mar 1;422(1):1-6. doi: 10.1016/j.ab.2011.12.051. Epub 2012 Jan 8.
We present here a resonance Rayleigh scattering (RRS) method for the determination of heparin at the nanogram level using gemini surfactant (dodecyl polyoxyethylene ether biquaternary ammonium salt, DPBAS). It was found that DPBAS could react with anionic heparin to form an ion-association complex, which induced the enhancement of RRS intensity and the appearance of a new RRS spectrum in Britton-Robinson buffer (pH 5.5). The RRS spectral characteristics of the heparin-DPBAS system, the optimum conditions of the reaction, and the influencing factors have been investigated. Under the optimum conditions, the enhanced RRS intensity (ΔI(RRS)) was proportional to the concentration of heparin in the range of 0.05-0.6μg/mL. The method has high sensitivity, and the detection limit for heparin is 4.3ng/mL. The proposed method has been successfully applied for the determination of heparin in pharmaceutical samples. Furthermore, the mechanism of the interaction between heparin and DPBAS was explored using RRS and conductivity methods, indicating that the gemini surfactant reacting with heparin mainly exists in the form of micellar-type aggregates. A model of the reaction between heparin and DPBAS molecules has been proposed.
我们在此提出了一种利用双子表面活性剂（十二聚氧乙烯醚双季铵盐，DPBAS）测定肝素的共振瑞利散射（RRS）方法，其检测限低至 4.3ng/mL。实验发现，DPBAS 可以与阴离子肝素发生反应，形成离子缔合物，从而增强 RRS 强度并在 Britton-Robinson 缓冲液（pH 5.5）中产生新的 RRS 光谱。我们研究了肝素-DPBAS 体系的 RRS 光谱特征、反应的最佳条件以及影响因素。在最佳条件下，RRS 强度的增强（ΔI(RRS))与肝素的浓度在 0.05-0.6μg/mL 的范围内呈正比。该方法具有较高的灵敏度，可用于测定药物样品中的肝素。此外，我们还使用 RRS 和电导法探讨了肝素与 DPBAS 之间相互作用的机制，表明双子表面活性剂与肝素的主要存在形式为胶束型聚集体。我们提出了肝素与 DPBAS 分子之间反应的模型。
