Researchers at the University of Tennessee have developed a biodiesel contamination detector. A news release from the school says the device, which can detect trace amounts of contamination, is the work of chemistry professor Ziling (Ben) Xue and doctoral student Jonathan Fong.

“The ability to detect biodiesel at various concentrations in diesel is an important goal in several industries,” said Xue. “There is particular concern over biodiesel contamination in jet fuel, because at higher levels it can impact the thermal stability and freezing point of jet fuel leading to deposits in the fuel system or gelling of the fuel. These issues can result in jet engine operability problems and possible engine flameout.”

Xue and Fong tested several dyes and found that the dye Nile blue chloride, dissolved in alcohol, can be made into a thin film with high sensitivity toward biodiesel contamination in jet fuel. They tested small strips of the sensor and found it could successfully detect amounts of biodiesel contaminant in diesel as low as 0.5 parts per million—ten times below the allowable limit of 5 ppm in the US—in less than thirty minutes.

The researchers point out the need for a quick and easy, direct way to detect biodiesel contamination because of the increasing safety needs in the vehicles biodiesel goes into. The new sensor can be used in a field-ready, portable reader.