Kindai University develops new method for rapid drug analysis from urine: 40 different drugs identified in 3 minutes

A research group led by Professor Kei Zaitsu of the Department of Computational Systems Biology, Faculty of Biology-Oriented Science and Technology at Kindai University (affiliated with Nagoya University at the time of the research), Senior Researcher Kazuaki Hisatsune of the Forensic Science Laboratory at Aichi Prefectural Police Headquarters, Senior Researcher Akira Iguchi of the National Institute of Advanced Industrial Science and Technology (AIST), Researcher Masaru Taniguchi of the Nagoya City Public Health Research Institute, and Lecturer Tomomi Asano of the Department of Human Life and Environment at Kinjo Gakuin University, announced the development of "RaDPi-U," a new method for rapid drug analysis from urine. The new method allows for direct analysis of 40 different drugs from a urine sample in 3 minutes, requiring no complicated or highly specialized operations. It is expected to be used in drug screening for drug-related crime investigations and acute drug intoxication. The results were published in the international academic journal Analytical and Bioanalytical Chemistry on March 25.

Drug analysis is required to prove ingestion of a controlled substance, such as methamphetamine or narcotics, during prosecution, or to detect possible acute drug intoxication for prompt treatment. In actual criminal investigations and poisoning accidents, even the individual of interest often does not know what drugs he or she has ingested. In these cases, simple immunoassay-based kits are typically used for initial drug screening analysis of urine at the scene of investigation or treatment. However, this method can only estimate a group of drugs with similar chemical structures and has limitations, such as the inability to determine the exact drug and occurrence of false positive results due to cross-reactivity. More advanced mass spectrometry methods are specialized and time-consuming.

The research group has been studying probe electrospray ionization tandem mass spectrometry (PESI/MS/MS), which enables rapid analysis of target components directly from animal biological samples. In this study, they used this technique to develop a new drug screening method that is as simple and ultra-rapid as an immunoassay but as sensitive as mass spectrometry. First, as target components, they selected 40 drugs that are most important in drug-related crime investigations. These drugs were selected mainly from among controlled substances such as methamphetamine, narcotics, benzodiazepine hypnotics, and psychoactive substances. They devised a method that allows the simultaneous analysis of these drugs to be completed in three simple steps.

In the new method, analysis is completed simply by (1) adding an internal standard solution (diazepam-d5) and a small amount of ethanol to 10 µl of a urine sample and stirring the mixture for 1 minute, (2) placing the sample in a special sample plate, and (3) pressing the PESI/MS/MS start button. Using the Scheduled-SRM method during mass spectrometry, multiple components can be analyzed simultaneously and mass spectrometry of 40 different drugs can be completed in 1.5 minutes. If the urine sample contains one of the 40 target drugs, their concentrations can also be calculated at the same time. Because results can be obtained in three simple steps, the methods can be used even by people unfamiliar with analysis and is thus expected to contribute to drug screening for drug-related crime investigations and acute drug intoxication.

Zaitsu said, "When drug-related poisoning accidents and crimes associated with drug abuse occur, great concern spreads among the public. A rapid analysis method is indispensable to promptly resolve such social concerns. To make the results of this research more useful to society, we will continue to refine the technique in cooperation with collaborative researchers at AIST, Aichi Prefectural Police Headquarters/Forensic Science Laboratory, Nagoya City Public Health Research Institute, and Kinjo Gakuin University."

Journal Information
Publication: Analytical and Bioanalytical Chemistry
Title: Development of a rapid-fire drug screening method by probe electrospray ionization tandem mass spectrometry for human urine (RaDPi-U)
DOI: 10.1007/s00216-024-05215-x