New MS-Based Technique Detects Drugs in Urine Samples
The rapid urine test can detect 40 drugs reliably in just three minutes and can also be applied in clinical toxicology tests

A research team from Kindai University, Japan, has developed a robust drug screening technique, called RaDPi-U, which can rapidly detect the presence of 40 drugs, including illegal drugs, hypnotics, and psychoactive substances from urine samples. The study, describing the technique and its performance in preliminary tests, was published recently in Analytical and Bioanalytical Chemistry.
Mass spectrometry-based drug detection
The RaDPi-U technique is based on a combination of probe electrospray ionization and tandem mass spectrometry (PESI-MS/MS). The procedure is relatively simple and involves about three key steps:
About 10 μl of the urine sample is mixed with a substance predetermined as an internal standard and ethanol.
After thoroughly vortexing the sample, the mixture is pipetted into a sample plate for PESI.
The plate is then set into rapid-fire analysis by PESI-MS/MS, which analyzes the sample in under three minutes and automatically reports results using built-in software.
Reliability and accuracy of the technique
The researchers investigated the reliability and accuracy of the results for multiple concentrations of each of the 40 screened drugs. Compared to established methods, RaDPi-U exhibited an equal or better lower limit of detection for all drugs: It can detect concentrations as little as fractions of a nanogram per microliter for several compounds.
They demonstrated the technique’s repeatability by using RaDPi-U to detect different drugs in three postmortem urine samples. Moreover, this method requires only one substance as an internal standard rather than a specific compound for each screened drug, simplifying the device setup.
“Our method boasts simplicity and user-friendliness, enabling even non-professionals to conduct drug analysis with ease,” said Kei Zaitsu, PhD, professor at Kindai University and one of the authors on the paper, in a recent press release. “In essence, our research streamlines drug analysis to unprecedented levels, thereby fostering long-term efforts to curb drug-related crimes.”
“While this study is preliminary and the number of currently detectable drugs is limited to 40, we are actively expanding the range of targeted substances, aiming to enhance both the speed and scope of detection,” added Dr. Kazuaki Hisatsune of the Forensic Science Laboratory at Aichi Prefectural Police Headquarters, Nagoya, Japan.