Roadside Drug Testing with Help from Chromatography

Chemistry researchers from the University of Surrey — in association with Advion Ltd and Surrey Borders Partnership NHS Foundation Trust — have developed a new diagnostic test for cocaine and benzoylecgonine in urine and oral fluids. The work potentially offers a method for a rapid roadside diagnostic test for cocaine. With over half of the drivers stopped for driving under the influence of banned drugs failing tests for illicit substances — the test could come at just the right time for the powers of law and order.

Chromatography and mass spectrometry

The researchers could demonstrate, for the first time, that it is possible to detect cocaine and its metabolites — including benzoylecgonine, the main metabolite — at levels below 30ng /ml using a compact mass spectrometer. The method will allow the use of lower cost and portable machines — making the method and equipment suitable for use in roadside testing.

The method they developed uses chromatography to separate the cocaine and its metabolites from the other compounds — and then uses a micro mass spectrometer to analyse the concentration of cocaine and its metabolites. The analysis of cocaine is discussed in the article, Review of Microsampling Techniques in Bioanalysis. Using chromatography helps with the subsequent mass spectrometry analysis by reducing ion suppression effects, which in turn increases the sensitivity of the analysis.

Low-level roadside detection

One of the advantages of the new method is that it can give quantitative data — many previous portable tests could not. They are based on antibody reagents which do not allow quantitative data to be collected. The cocaine antibody can also bind to other substances, not just cocaine, which can produce false positive results.

The new method was found to give a detection limit below the level normally used for oral fluid drug testing — in essence, the test can detect very low levels of cocaine in a sample, either of urine or saliva. Coupled with the use of the micro mass spectrometry, this allows the test to be considered suitable for portable drug testing — either roadside testing by police or drug testing in workplaces.

In a press release from the University of Surrey, the paper’s lead author explains:

“Surface mass spectrometry is used in a wide range of disciplines to obtain chemical information from the surface of a sample. However, until now it has not been possible to translate this method to low cost, portable testing. This new method, which extracts analytes from a surface and separates them using chromatography, has been shown to provide a sensitive, accurate result.”

The team plan to test the system and method’s efficacy using other drugs of abuse. Someday soon, a police officer could be using the method by the side of a road near you.