Abstract
We developed a method based on liquid chromatography coupled with tandem mass spectrometry to quantify individual enantiomers of methadone and its primary metabolite, R/S-2-ethyl-1,5-dimethyl- 3,3-diphenylpyrrolinium (EDDP), in postmortem blood and brain tissue. Samples were prepared with a Tecan Evo robotic system. Precipitation was followed by solid-phase extraction, evaporation and reconstitution in the mobile phase. Enantiomers were fully separated with liquid chromatography on a chiral a(1)-acid glycoprotein column. A Quattro micro mass spectrometer was used for detection in the positive ion mode with an electrospray source. The lower limit of quantification in brain tissue was 0.005 mg/kg for methadone and 0.001 mg/kg for EDDP enantiomers; the maximum precision was 17% for both compounds; accuracy ranged from 94 to 101%. In blood, the limit of quantification was 0.001 mg/kg for all compounds, the total relative standard deviation was <15%, and the accuracy varied from 95 to 109%. Brain (n 5 11) and blood (n 5 15) samples were analyzed with intermediate precision that varied from 7.5 to 15% at 0.005 mg/kg and from 6.8 to 11.3% at 0.25 mg/kg for all compounds. Method development focused on producing a clean extract, particularly from brain samples. The method was tested on authentic brain and femoral blood samples.
| Translated title of the contribution | Chiral Analyse af methadone og dennes hovedmetabolit, EDDP, i Postmortem Hjerne og Blod ved Automatisk SPE og Væskekromatografi-Massespektrometri |
|---|---|
| Original language | English |
| Journal | Journal of Analytical Toxicology |
| Volume | 36 |
| Issue number | 21 |
| Pages (from-to) | 487-496 |
| Number of pages | 10 |
| ISSN | 0146-4760 |
| Publication status | Published - 1 Sept 2012 |
Keywords
- Faculty of Health and Medical Sciences