Introducing Acid–Base Titration on Paper-Based Analytical Devices in a High-School Chemistry Laboratory for the Determination of Acetylsalicylic Acid

In this study, paper-based analytical devices (PADs) were used to introduce a simple, rapid, portable, and low-cost acid–base titration method in high school chemistry laboratories. Students performed conventional and paper-based titrations to determine the amount of acetylsalicylic acid in aspirin® tablets. This learning laboratory experiment aimed to introduce the concept of PADs and fundamentals of acid–base titrations to students, as well as to evaluate their perceptions of both titration methods, such as portability, waste generation, solution volume consumption, and how it contributed to their learning experience and skills through a questionnaire. Thirty-two high school students conducted this laboratory experiment over four 90 min classes during the second semester of 2025. The students’ assessment was very satisfactory, and in general, this laboratory experiment contributed to their learning experience during high school.