动态紫外光谱法检测湿巾无纺布对苄索氯铵杀菌剂的吸附

生产中苄索氯铵在湿巾中的添加是通过药液浸渍的方式，即无纺布对药液中苄索氯铵分子的吸附而实现的。由于苄索氯铵的吸附是一个时间很短的动力学过程，目前关于无纺布对苄索氯铵吸附速率的研究还未见报道。以湿巾无纺布对溶液中苄索氯铵的吸附为研究对象，根据苄索氯铵在波长269 nm处存在特征吸收峰，通过搭建在线动力学紫外监测平台，利用蠕动泵将溶液输送到紫外分光光度计的流动比色皿进行循环检测，可实现对吸附过程中苄索氯铵溶液吸光度值的在线实时检测；根据苄索氯铵吸光度值与浓度的关系，推导计算得出苄索氯铵吸附量，从而实现了无纺布对苄索氯铵吸附速率的快速准确检测。该方法适用于在线监测无纺布对苄索氯铵吸附时药液浓度变化。结合Weber and Morris内扩散动力学模型，对苄索氯铵的吸附过程进行理论分析，为深入研究无纺布对苄索氯铵的吸附做指导。结果表明：无纺布对苄索氯铵的吸附是一个连续性的分散过程；第一阶段的苄索氯铵线性吸附与表层扩散有关，第二阶段为苄索氯铵扩散过程，第三阶段是苄索氯铵吸附与脱附的平衡动态过程，且第一阶段扩散率常数（41.60）远大于第二阶段的扩散率常数（15.63），说明表层扩散在整个吸附过程中起了很重要的作用。研究工作对于湿巾生产过程中及时合理的添加苄索氯铵及优化湿巾生产工艺具有现实的指导意义。

Adsorption of Benzethonium Chloride Fungicide on Nonwoven Wipes by Kinetic Ultraviolet-Visible Spectroscopy

In the process of production, the addition of benzethonium chloride to the wipes is achieved by impregnation of the pharmaceutical solution, that is, the adsorption of benzethonium chloride molecules in the pharmaceutical solution by nonwovens. Because the process of benzethonium chloride adsorption is a very short time, the study about the adsorption rate of benzethonium chloride by nonwovens has not been reported. In our work, the adsorption of benzethonium chloride by nonwoven was as research subject, and according to the fact that the characteristic absorption peak of benzethonium chloride was at 269 nm, by building an on-line kinetic ultraviolet-visible spectroscopy monitoring system and using a peristaltic pump to transport the solution to the flow cuvette of the spectrophotometer for cyclic detection, the absorbance value of benzethonium chloride solution in the adsorption process can be determined online. Based on the relationship between the absorbance value and benzethonium chloride, the adsorption of benzethonium chloride was deduced and calculated. Therefore, a method for the accurate and rapid determination of benzethonium chloride adsorption by nonwoven was established, which is suitable for on-line monitoring of the concentration of benzathonium chloride solution. The adsorption process of benzethonium chloride was theoretically analyzed by Weber and Morris diffusion model, which provides guidance for further study on the adsorption of benzethonium chloride by nonwovens. The results showed that the adsorption of benzethonium chloride is a continuous dispersion process; The first stage of linear adsorption is related to the surface diffusion, the second stage is the intergranular diffusion process and the third stage is the equilibrium dynamic process of adsorption and desorption. The diffusivity constant of the first stage (41.60) is much higher than that of the second stage (15.63), indicating that surface diffusion plays an important role in the whole adsorption process. This paper can provide good guidance for rational selection of benzethonium chloride concentration and optimization of process in production of wet wipes.