A new colorimetric paper-based detection of furfural vapor as a fuel marker

Abstract

Conventional fuel dye markers used in prevention of fuel smuggling and unauthorized mixing generally require laborious sample preparation including extraction and mixing of color developer in liquid phase which also generate high waste volume. In this work, furfural is used as an economical fuel marker which can be directly detected in vapor phase without extraction providing low waste generation. The ambient vapor pressure of furfural allows adequate amount of the marker to be captured by filter paper coated with amine color developers and detected by smartphone camera for colorimetric quantification using ImageJ processing software. The color is developed by either the Stenhouse reaction or imine condensation of amine with furfural in the presence of an appropriate acid. The dynamic quantification range of furfural marker in gasoline fuel is 5–35 ppm with the detection limit at 3.10 ppm.