A Numerical Analytical Model for Multi-Ion Detection Applied to Solid-State Contact Ion-Selective Electrode Array

Water is a basic component of nature and an important substance for the survival of the biosphere. With the development of science and technology and people's increasing concern for the environment, the demand for water quality testing is increasing. Driven by the progress of micromachining technology, the solid contact ion selective electrode (SC-ISE) was born and flourished, gradually replacing the traditional liquid contact ion selective electrode. In particular, it has the characteristics of high integration and simple process, and more and more related portable online detection applications have been reported. However, most of the current applications are based on the selectivity of the ion-selective membrane itself, and the interference problem is ignored in specific scenarios, which reduces the accuracy of the detection results and limits the application scenarios. Based on the experimental phenomena, this paper proposes a numerical model to analyze the ion concentration problem in the scenario where multiple ions interfere with each other. In addition, a parallel channel data selection method is proposed to reduce the impact of accidental errors. As a carrier, we designed a multi-ion and multi-channel solid contact ion-selective electrode array to detect calcium, magnesium, sodium and potassium ions in actual water samples, and compared with the high-precision ICP-OES detection results. The scientificity and applicability of the numerical model are verified within the acceptable range of error.