A practical tutorial for optimizing electromembrane extraction methods by response surface methodology

Microextraction techniques, such as electromembrane extraction (EME), have greatly advanced analytical chemistry by providing efficient, cost-effective, and eco-friendly sample preparation methods. EME is especially promising for ionizable analytes, with its success relying on optimizing multiple experimental variables. Traditionally, optimization has employed a one-variable-at-a-time (OVAT) approach, which is time-consuming and may overlooks variable interactions. This tutorial introduces response surface methodology (RSM) as a superior alternative for optimizing EME methods. RSM allows for the simultaneous variation of multiple factors, offering a comprehensive understanding of their effects and interactions with fewer experiments. This tutorial covers the fundamental principles of EME, essential experimental parameters, and the application of RSM for method optimization. It includes guidance on software selection, design choice, factor settings, response definition, and the optimization of multiple responses. Practical steps for conducting experiments, analyzing data, and interpreting models are detailed, with real-life examples illustrating the process. The tutorial aims to make RSM accessible to both novice and moderately experienced users, promoting its broader application in analytical chemistry. By simplifying the complex optimization process, this tutorial supports the development of robust, efficient, and green EME methods.