While there are already portable systems designed to detect cocaine in peoples' systems, the devices can't tell how much of the drug has been taken. Additionally, they sometimes produce false positives – they say that cocaine is present when it isn't. That's where a new test designed by the University of Surrey and Advion Ltd comes in. Not only is it reportedly more reliable than existing technology, but it also measures quantities of cocaine in the body.

Designed to be administered quickly and inexpensively at sites such as roadside checkstops, workplaces or prisons, the test incorporates a miniature mass spectrometer made by Advion.

A urine or saliva sample is placed in the device, which uses chromatography to separate cocaine from other compounds within that sample – and to see how much of it is present. The spectrometer also measures levels of benzoylecgonine, a chemical which is created by the body when cocaine is metabolized.

By contrast, traditional portable tests typically use antibody reagents that bind to cocaine. The problem is, those tests don't differentiate between large and small amounts, plus the antibodies can also bind to other substances, creating false positive readings.

"Surface mass spectrometry is used in a wide range of disciplines to obtain chemical information from the surface of a sample," says PhD student Mahado Ismail, lead author of a paper on the study. "However until now it has not been possible to translate this method to low cost, portable testing."

The scientists are now looking at applying the technology to testing for other illicit drugs. Their paper was recently published in the journal Analytical Methods.

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