The fight against drug abuse requires reliable, convenient and cost-effective methods of drug analysis. A new technique developed by Hong Kong Polytechnic University (China) promises just that. The technique, Wooden-tip Electrospray Ionization Mass Spectrometry (WT-ESI-MS), is capable of rapid detection of four common drugs-of-abuse: ketamine, methamphetamine, MDMA and cocaine.
Compared with conventional drug testing, which can take several hours to analyze a single sample, WT-ESI-MS can produce accurate analysis of urine and oral fluid within minutes, providing identification and quantification of the drugs-of-abuse present in the sample. The new technique is simpler, faster, more reliable than conventional techniques, and also cost effective owing to the significant reductions in time and cost required for the analysis.
Conventional drug testing is a two-stage process, involving preliminary screening followed by confirmatory analysis. The preliminary screening stage using test kits has been known to produce false-positive or false-negative results, while confirmatory analysis requires extensive sample pretreatment and chromatographic separation prior to mass spectrometry. It is therefore hoped that the new test could reduce the cost, time and errors associated with current drug analysis.
In WT-ESI-MS, household wooden toothpicks replace the conventional capillary system of sample introduction in mass spectrometry. Wooden tips can reduce interference from other substances and are free from the clogging that can occur in capillary tips. Mass spectrometric analysis of drugs in urine and oral fluid can therefore take place without sample pretreatment and chromatographic separation, improving the ease and speed of analysis.
The research team’s results demonstrate that their technique is effective and reliable for the detection and quantification of ketamine, methamphetamine and MDMA in urine and oral fluid, as well as cocaine in oral fluid.
They plan to continue to develop more sensitive analytical methods for rapid and reliable drug analysis, and to expand the technique to detect other drugs-of-abuse such as cannabis and heroin. They also intend to develop a portable analysis device in the near future.
Source: So PK, Ng TT, Wang H, Hu B, Yao ZP. Rapid detection and quantitation of ketamine and norketamine in urine and oral fluid by wooden-tip electrospray ionization mass spectrometry. Analyst 138(8), 2239–2243 (2013); PolyU develops a new technique for rapid detection of drugs-of-abuse.