Enantioselective analysis of methadone in saliva by liquid chromatography-mass spectrometry

Saliva was tested and evaluated as a biological matrix for methadone (Mtd) monitoring. Conventional method using a narrow bore C-18 column, and an ena ntioselective method using a narrow bore alpha(1)-acid glycoprotein column, were developed using liquid chromatography coupled with a mass spectromeri c (MS) detector. After optimisation of MS conditions by flow injection anal ysis, selected ion monitoring detection was used to enhance sensitivity. Th e total Mtd concentration and the enantiomeric ratio in saliva were validat ed using an experimental design. The methods were applied to samples provid ed by heroin addicts undergoing a Mtd treatment. Results on total Mtd deter mination showed a very poor correlation between saliva and serum, whereas t he enantiomeric ratios of Mtd gave a very good one. (C) 2000 Elsevier Scien ce B.V. All rights reserved.