A group of researchers from Sweden have provided further
evidence that illegal drugs can be detected in the breath, opening up the
possibility of a roadside breathalyser test to detect substances such as
cocaine, amphetamines and cannabis.
Using a simple, commercially available breath sampler, the
researchers have successfully identified a range of 12 substances in the breath
of 40 patients recruited from a drug emergency clinic in Stockholm.
Their findings have been published, in IOP Publishing'sJournal of Breath Research.
The new alternative
Blood, urine and saliva are the most popular methods for
detecting illegal drugs and are already used by law enforcement in a number of
countries; however, exhaled breath is seen as a promising alternative as it's
easier to collect, non-invasive, less prone to adulteration and advantageous
when location becomes an obstacle, such as at the roadside.
Exhaled breath contains very small particles that carry
non-volatile substances from the airway lining fluid. Any compound that has
been inhaled, or is present in the blood, may contaminate this fluid and pass
into the breath when the airways open. The compounds will then be exhaled and
can subsequently be detected.
In this study, researchers from the Karolinska Institute in
Stockholm collected breath, blood plasma and urine samples from 47 patients (38
males, 9 females) who had taken drugs in the previous 24 hours and were
recovering at a drug addiction emergency clinic.
Interviews were also undertaken with each patient to assess
their history of drug use.
The breath samples were taken using a commercially available
sampling device – SensAbues – and then analysed using liquid chromatography and
How it works
The portable sampling device consists of a mouth piece and a
micro-particle filter. When a patient breathes into the mouth piece, saliva and
larger particles are separated from the micro-particles that need to be
The micro-particles are able to pass through and deposit
onto a filter, which can then be sealed and stored ready for analysis. Breath
samples were analysed for twelve substances.
Alprazolam and benzoylecgonine were detected in exhaled
breath for the first time, whereas for methadone, amphetamine, methamphetamine,
cocaine, morphine, 6-acetylmorphine, tetrahydrocannabinol, buprenorphine,
diazepam and oxazepam, the results confirmed previous observations.
"Considering the samples were taken 24 hours after the
intake of drugs, we were surprised to find that there was still high
detectability for most drugs," said lead author of the study Professor
"In cases of suspected driving under the influence of
drugs, blood samples could be taken in parallel with breath when back at a
police station. Future studies should therefore test the correlation between
blood concentration of drugs of abuse and the concentrations in exhaled