Rapid Acid Value Test-Kit Development for Oleochemical Product Quality Control Using Microfluidic Technology

This paper describes the design and implementation of a cost effective micro total analytical devices (μTADs) that aims to determine the acid value of oleochemcial product. This device aims to provide a simple and effective acid-base titration technique in an aqueous solution in microscale. The device utilised colorimetry approach to determine the acid value of the oleochemical product by measuring the distance travelled by the colour change from pink to colourless during titration to quantify the molarity of the acid concentration. The μTADs consists of a 3D-printed polymeric design holder and a chemically treated cotton thread. The thread will show color change when different acid sample is dropped onto the thread. The distance of colour change is plainly visible with naked eyes and measured using a ruler scale in 2 minutes. The developed μTADs on acid value for samples from the oleochemical sector demostrated 98% accuracy, as compared to conventional titration process. In addition, the μTADs can improve significantly in terms of chemical used by reducing the reagent requirement by 99.5%, as well as a further cost reduction of 143 folds while maintining the accuracy of acid value measurement. This work provides a great alternative solution to acid value determination at a faster, more portable, and customizable technique that required less technical experience.