Shanghai University invents THz gutter oil detector

http://english.eastday.com/e/121024/u1a6943091.html
UNIVERSITY researchers in Shanghai have achieved a major breakthrough in detecting gutter oil, which is recycled illegally by some eateries.
The new method has been listed by the Ministry of Health as one of the final candidates that could be adopted nationwide, university officials announced yesterday.
A Terahertz (THz) wave is filtered through the oil sample to find out the vibration frequency of the oil so as to analyze its ingredients, according to the University of Shanghai for Science and Technology.
The vibration frequency of gutter oil, made from kitchen waste and dead animals, differs greatly from edible oil, researchers said.
"It only takes one minute for the detection," said Zhu Yiming, deputy director of the university's School of Optical-Electrical and Computer Engineering.
The ministry provided more than 70 oil samples to the researchers to check and they successfully detected the kind of oil in 90 percent of them.
The portable gutter oil detector will be one of the highlights at the China International Industry Fair 2012, which will be held at the Shanghai New International Expo Center from November 6 to 10.