**Chapter 8**

Electrochemical Impedance Spectroscopy (EIS) in Food, Water, and Drug Analyses: Recent Advances and Applications *by Marwa El-Azazy*

Preface

Electrochemical impedance spectroscopy (EIS) is a potent electrochemical

This book introduces readers to the basic principles of EIS with a focus on recent developments and applications. The book is divided into eight chapters, which in turn coalesce the application of EIS in different fields. Chapter 1 by Hernández et al. provides readers with comprehensive information on the use of EIS in monitoring and hence controlling the corrosion of steel. In Chapter 2, Sawadogo et al. investigates the application of EIS in studying and managing the corrosion behavior of recycled aluminum alloy in various culinary media. Chapter 3 by Almzarzie et al. studies the use of a non-toxic and ecofriendly corrosion inhibitor extracted from turmeric roots. Kouass et al., in Chapter 4, use EIS to analyze the design of multi-ionic doped CePO4 materials with improved ionic conductivity and electrochemical stability. Chapter 5 by Gheorghe et al. discusses the circuit models of bioelectric impedance. This chapter shows an interesting application of EIS in medicine, where in various applications accurate information about fluid distribution in different compartments of the body may lead to substantial conclusions. Chapter 6 by Aldosky et al. reviews another application of EIS as a non-invasive technique, as well as the use of electrodermal activity (EDA) as a sensitive measure of sympathetic nervous system activity. Elmelouky et al., in Chapter 7, study environmental applications of EIS and the adsorption behavior of nitrate ions by layered double hydroxide. Finally, in Chapter 8, El-Azazy conducts a thorough review of applications of EIS in food,

I would like to use this opportunity to thank my co-editors Prof. Mart Min and Dr. Paul Annus for their great efforts in reviewing and editing the book. I am entirely indebted to all the authors for their valuable contributions. The contributors are experts in their respective fields and have tried their best to disclose the inherent concepts related to the applications covered in this volume.

Their efforts to make this book comprehensive and informative are much

I am most grateful to Author Service Manager Mr. Mateo Pulko for all his efforts and support throughout the process of editing this book. Many thanks to the entire

widespread use of EIS in a variety of applications.

water, and drug analysis.

appreciated.

technique with a variety of applications. EIS measurements involve the application of an alternating current (AC) to the system under investigation, followed by measurement of the response in the form of AC current (or voltage) as a function of frequency. In general, three factors make EIS exceptionally attractive in terms of applications: (1) capability to explore electrochemical systems (ES) at relatively low frequencies, in contrast to the majority of electrochemical techniques, which involve an application of large perturbation for sensing the membrane/electrolyte interface; (2) feasibility of implementation of EIS into the system to be measured; and (3) usefulness of data obtained in characterizing the studied ES, where EIS provides on-site information on the relaxation data over a range of frequencies, from as low as 10-4 Hz up to 106 Hz. A combination of these advantages led to the

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