Smartphone-Based Video Dataset of Colorimetric Reactions between Phenolic Compounds and Ferric Chloride: A Case Study on Gallic Acid

Abstract

Colorimetric assays for phenolic compounds are widely employed due to their simplicity and reliability, particularly when using ferric chloride (FeCl₃) as a reagent. This study presents a curated video dataset documenting the reaction of gallic acid with 0.5 % FeCl₃, captured across multiple smartphones to assess reproducibility and cross-device variability. Gallic acid solutions ranging from 0.001 % to 1 % (w/v) were tested, producing a blue-black complex with intensity proportional to concentration. The dataset comprises 63 short video clips recorded using three smartphones (POCO C75, OPPO A3, Realme C73) under identical acquisition parameters. Each 15-second video captures the reaction kinetics from initial contact to stabilization. The dataset provides an open benchmark resource for developing machine learning algorithms in digital phenolic sensing, exploring cross-device calibration, and serving as a teaching tool for chemistry education.