A novel method for electroosmotic flow (EOF) measurement on paper substrates is presented; it is based on dynamic mass measurements by simply using an analytical balance. This technique provides a more reliable alternative to other EOF measurement methods on porous media. The proposed method is used to increase the amount and quality of the available information about physical parameters that characterize fluid flow on microfluidic paper–based analytical devices (μPADs). Measurements were performed on some of the most frequently used materials for μPADs, i.e., Whatman #1 , S&S, and Muntktell 00A filter paper. Obtained experimental results are consistent with the few previously reported data, either experimental or numerical, characterizing EOF in paper substrates. Moreover, a thorough analysis is presented for the quantification of the different effects that affect the measurements such as Joule effect and evaporation. Experimental results enabled, for the first time, to establish well‐defined electroosmotic characteristics for the three substrates in terms of the magnitude of EOF as funtion of pH, enabling researchers to make a rational choice of the substrate depending on the electrophoretic technique to be implemented. The measurement method can be described as robust, reliable, and affordable enough for being adopted by researchers and companies devoted to electrophoretic μPADs and related technologies.

中文翻译：

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在纸质基材上进行精确的电渗流量测量

提出了一种在纸质基材上进行电渗流 (EOF) 测量的新方法；它基于动态质量测量，只需使用分析天平即可。该技术为多孔介质上的其他 EOF 测量方法提供了更可靠的替代方法。所提出的方法用于增加有关物理参数的可用信息的数量和质量，这些物理参数表征了基于微流体纸的分析设​​备 (μPAD) 上的流体流动。对一些最常用的 μPAD 材料（即 Whatman #1、S&S 和 Muntktell 00A 滤纸）进行了测量。获得的实验结果与先前报道的少数数据一致，无论是实验数据还是数值数据，都表征了纸基材中的 EOF。而且，对影响测量的不同影响（如焦耳效应和蒸发）进行了全面分析。实验结果首次能够根据 EOF 的大小作为 pH 的函数来确定三种底物的明确电渗特性，使研究人员能够根据要实施的电泳技术合理选择底物. 该测量方法可以被描述为稳健、可靠且价格合理，足以被致力于电泳 μPAD 和相关技术的研究人员和公司采用。根据 EOF 的大小作为 pH 值的函数，确定三种底物的明确电渗特性，使研究人员能够根据要实施的电泳技术合理选择底物。该测量方法可以被描述为稳健、可靠且价格合理，足以被致力于电泳 μPAD 和相关技术的研究人员和公司采用。根据 EOF 的大小作为 pH 值的函数，确定三种底物的明确电渗特性，使研究人员能够根据要实施的电泳技术合理选择底物。该测量方法可以被描述为稳健、可靠且价格合理，足以被致力于电泳 μPAD 和相关技术的研究人员和公司采用。