Malcolm C., Oliver J.S.

Department of Forensic Medicine and Science, University of Glasgow, Glasgow, G12 8QQ, Scotland, UK

The use of saliva as a biological matrix for drug screening provides a non-invasive method of sampling. In order to assess the validity of saliva for this purpose it is necessary to determine the saliva/blood ratio. This paper describes the evaluation of the saliva/blood ratio for methadone.
Subjects were registered on a methadone maintenance programme at the Drug Crisis Centre, Glasgow and consented to having blood and saliva samples taken 24 hours after oral administration of methadone. The saliva samples were collected from the patients using a saliva collection device called an Omni-SAL^® (Saliva Diagnostic Systems). Methadone was quantified using a solid phase extraction procedure with Bond-Elut Certify^® columns followed by Gas Chromatography/Mass Spectrometry.
Factors affecting the saliva/blood ratio will be discussed enlight of the results.