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Testing for cocaine and other drugs usually involves two steps: a quick on-site prescreen and then a more accurate confirmatory test at a laboratory.

This process can often take days or weeks — far too long in many cases where public safety can be at risk.

Now, a team of researchers report development of a backpack-sized device that can perform highly accurate and sensitive tests anywhere within 15 minutes. The study appears in the American Chemical Society’s journal Analytical Chemistry.

91�Թ� chemist Aaron Wheeler and colleagues explain that the current two-stage system of testing urine for commonly abused drugs 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.

“We are moving into a world in which chemical analysis will be everywhere — the ‘lab’ will be wherever you are,” said Wheeler. “Some analyses will be implemented using a simple dipstick format like in a pregnancy test, while others will require a ‘portable laboratory.’”

Currently, when urine 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.

The team put together a compact system that can do all the steps — extracting commonly abused drugs from urine with a microfluidic device coupled to a small mass spectrometer that can identify the substances. The new backpack-sized instrument could analyze cocaine, benzoylecgonine — the main metabolite of cocaine used in drug screening tests — and codeine in four samples in less than 15 minutes.

“The amount of cocaine we can detect is compatible with limits set by the United Nations Office on Drugs and Crime,” said Wheeler. “We expect that our device could be used for many different kinds of tests in which laboratory-quality results are needed quickly and wherever you happen to be.”

The project is a joint initiative of the Wheeler Microfluidics Laboratory at 91�Թ� and R. Graham Cooks, the Henry B. Hass Distinguished Professor of Analytical Chemistry at Purdue University. Other members of the research team include Andrea E. Kirby, Nelson M. Lafrenière and Brendon Seale of the Wheeler Lab and Paul I. Hendricks of Purdue University. Research was funded by the Natural Sciences and Engineering Council of Canada (NSERC) and the U.S. National Science Foundation.

With files from the American Chemical Society