Testing for cocaine and other drugs usually involves two steps: a quick on-site prescreen, and then a more accurate confirmatory test at a distant laboratory. This process can take days or weeks - but that's too long in many cases where public safety is at risk. Now, researchers report development of a backpack-sized device that can perform highly accurate and sensitive tests anywhere within 15 minutes. The study appears in ACS' journal Analytical Chemistry.
Aaron Wheeler and colleagues explain that the current two-stage system of testing urine for drugs of abuse is expensive and time-consuming. The samples also could get lost or compromised while in transport. The ideal solution, they say, is to skip the prescreening step and instead bring the lab to the site - but in an easy-to-use, portable package. Currently, when samples arrive at labs for confirmation testing, trained technicians use a "gold-standard" method, relying on sample processing, liquid chromatography and mass spectrometry to analyze them. Small versions of instruments that implement these techniques can provide results at or near lab-quality, but they haven't been optimized and tested together as a single, portable instrument. Wheeler's team set out to do just that.
They put together a compact system that can do all the steps - extracting drugs of abuse from urine with a microfluidic device coupled to a small mass spectrometer that can identify the substances. The backpack-sized instrument could analyze cocaine, benzoylecgonine (a metabolite of cocaine) and codeine in four samples in less than 15 minutes. The amount of cocaine they could detect was compatible with limits set by the United Nations Office on Drugs and Crime. The researchers say the device could be used for many different kinds of tests in which laboratory-quality results are needed quickly.