Development Of Breath Tests For Drugs
February 4, 2006 - medicalnewstoday.com
A series of preliminary studies into the detection of breath markers of drugs is being undertaken at Keele University Medical School using a revolutionary form of breath analysis (SIFT-MS) which has been invented by Professor David Smith FRS and Professor Patrik Spanel from the Institute of Science and Technology in Medicine (ISTM) at Keele. This patient friendly non-invasive SIFT-MS technique allows the sampling of single exhalations of breath in real time avoiding the collection of breath samples into bags, which is required for other techniques and which compromises the breath sample. Thus, SIFT-MS data is immediately available to the clinician for rapid diagnosis. These novel instruments are now manufactured by Trans Spectra Limited of which Professors Smith and Spanel are co-founders and directors. They are now being used to investigate several diseased states, including renal failure, diabetes and cancer, using breath analysis.
The experiments on cannabis are part of a joint research project with Dr Roger Bloor, Senior Lecturer in Addiction Psychiatry at Keele and the ISTM team, including Dr. Tianshu Wang, and are part of the first stages of a programme of research focusing on the development of a methodology for the detection of drugs through breath sampling. Studies of two drugs, Cannabis and Gamma Hydroxybutyric acid (GHB), have been the focus of the current research.
The size of the molecules in Cannabis are beyond the range of the current SIFT-MS detection system and this study explores identification of smaller marker molecules which result from breaking down the large molecules during the SIFT-MS analysis.
These results show that SIFT-MS is able to detect markers for cannabis in both the air above drug samples and in the vapor and smoke produced when cannabis is heated or burnt. The ability to detect markers of cannabis use on the breath will depend on the how long these markers are retained in breath following cannabis use. Cannabis has previously been detected from breath samples of human subjects by gas chromatography/mass spectrometry (GC/MS) up to twelve minutes after smoking marijuana. Using chemical detection methods, cannabis has been reported to be detectable on breath samples up to 2 hours after smoking cannabis, but with many false positive results from a variety of other substances.
The current project, which has been funded by the North Staffs Medical Institute Research Grant and by the North Staffordshire Research and Development Consortium, will continue by analysing the gases above the urine of subjects smoking cannabis to attempt to identify additional marker substances. Breath samples will then be obtained from subjects using cannabis that will be analysed by SIFT-MS techniques.
Ethical approval has been granted by the Local Research Ethics Committee for analysis of breath and urine samples from patients attending for treatment of drug addiction. The cannabis samples used are held under a Home Office Licence and have been supplied from seized drug samples through cooperation with Staffordshire Police.