Čes. slov. farm. 2008, 57(6):265-268

Optimization of the extraction method for the determination of methadone and its metabolite EDDP in urine by gas chromatography

R. Horáková^*, J. Valentová, I. Pechová, F. Devínsky

Univerzita Komenského Bratislava, Farmaceutická fakulta, Katedra chemickej teórie liečiv

The present study aimed to develop a suitable extraction method for the determination of methadone and it's metabolite EDDP in human urine by gas chromatography with a nitrogen-phosphorus detector (NPD). The extraction method was optimized in an effort to receive the most satisfactory yield of the mentioned compounds from human urine. The highest yields were obtained by alkaline extraction (~ pH 9) with dietylether. Proadiphene (PA) was used as the internal standard. The most efficient yields were determined as follows: 91 ± 5 % for methadone (MTD) and 86 ± 5 % for its metabolite EDDP. The detection limit (LOD) of MTD was 8 ng/ml, for EDDP 23 ng/ml, and the limit of quantification (LOQ) was 27 ng/ml of MTD and for EDDP 77 ng/ml. The accuracy of this method inter day was found for MTD 1.1-2.32 %, for EDDP 7.3-9.3 % and intra day for MTD it was 9.1-13.7 %, for EDDP 4.7-8.7 %. The suitability of the developed method was checked for routine monitoring of MTD and it's metabolite EDDP in human urine for 5 different samples taken from methadone maintenance program.

Keywords: methadone (MTD); 2-ethylidene-3,3-diphenyl-1,5-dimethylpyrrolidine (EDDP); urine; GC, NPD

Grants and funding:

Táto práca bola riešená za podpory grantov VEGA č. 1/3416/06, 1/4300/07 a grantu APVV č. 20-030804.

Received: September 25, 2008; Accepted: October 29, 2008; Published: June 1, 2008  Show citation