SHENYANG, Aug. 21 -- Chinese scientists announced Wednesday that they had developed a portable mass spectrometer for rapid on-site detection of drug mixtures.

The 13-kg gadget is 32 cm long, 32 cm wide and 24 cm tall, and has built-in batteries which can be used for three hours of field operation.

It was developed by the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences, in collaboration with the Yunnan Police College and a laboratory of the Ministry of Public Security.

In mixtures, boiling points of different drugs vary greatly. The volatile ones have low sensitivity and may disappear at any time in the detection, making it difficult to detect components of drug mixtures.

The research team reports a synchronized flash-thermal-desorption purging and ion injection method to increase the sensitive and rapid screening of volatile and nonvolatile illegal drugs for miniature ion tap mass spectrometry.

The flash-thermal desorption could reach 290-degrees centigrade in 2.5 seconds, which could achieve efficient vaporization of nonvolatile noscapine with a boiling point of 565-degrees centigrade.

According to the team, ten kinds of mixing drugs with a boiling point difference of 300-degrees centigrade can be simultaneously identified within three seconds under a single analysis.

The gadget successfully identified 37 kinds of drugs during tests in southwest China's Yunnan Province.

The study has been published on the recent issue of the American Journal of Analytical Chemistry.