Illegal drug smugglings and crimes have long been a global concern. Anti-drug is the most effective and widely used method in the world, although it is not the fundamental solution to the drug problem.

The premise of drug control is drug identification, and law enforcement departments have an urgent need for the technology and equipment that can rapidly identify the presence of illegal drugs.

Prof. LI Haiyang’s and Prof. HOU Keyong’s group at the Dalian Institute of Chemical Physics of Chinese Academy of Sciences, collaborating with Yunnan Police Officer Academy, and Drug analysis and Drug Control Technology Key Laboratory of the Ministry of Public Security, developed a thermal acetone-assisted photoionization miniature ion trap mass spectrometer, realizing the rapid on-site detection of illegal drugs in complex matrix. The study was published in Anal. Chem. 

Acetone was chosen for dopant assisted photoionization and greatly improved the ionization efficiency. The mass discrimination effect, which was usually considered as a shortcoming of ion trap mass analyzer, was ingeniously utilized to eliminate the protonated acetone reagent ions and maximize the trapping efficiency of analyte ions in mass analyzer. Analyte/dopant ion peak intensity ratios in mass spectra could be used for quantitation to improve the quantitative analysis performance of miniature ion trap mass spectrometer.

A temperature-resolved thermal desorption sampling strategy was developed and used to distinguish illegal drug components in plant-based drug samples and drinks containing illegal drugs.

Twenty-seven drugs were analyzed and the limits of detections (LODs) of selected illegal drugs were at the nanogram level.

During the development process, the mass spectrometer has been used in multiple Frontier Inspection Stations in Yunnan province, such as Mukang Frontier Inspection Station in Dehong Autonomous Prefecture, and Qinglongchang Frontier Inspection Station in Yuxi City. Valuable experience was gained for the study of ion trap mass spectrometry in drug detection and the improvement of instrument performance.

Schematic diagram of the thermal desorption acetone-assisted photoionization ionization source and the 2D mass spectra of opium ointment. (Image by WANG Shuang)