Solid-phase extraction of methadone enantiomers and benzodiazepines in biological fluids by two polymeric cartridges for liquid chromatographic analysis.
The aim of this work was to present the advantages of two polymeric cartridges (Oasis HLB from Waters and Abselut Nexus from Varian) for the solid-phase extraction of methadone enantiomers and its major metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and of some benzodiazepines (diazepam, flunitrazepam, nitrazepam, oxazepam) in serum and urine in comparison with classical C18-bonded-silica cartridges or liquid extraction. After addition of serum or urine samples, these two cartridges were washed with a water-methanol mixture (95:5, v/v) and eluted with diethylether. After rapid evaporation, the residue was regenerated with mobile phase and injected either in a chiral column (Cyclobond I-2000 RSP) for methadone enantiomers and its metabolite or in a reversed-phase column (Symmetry Shield RP8) for benzodiazepines. The results showed that the chromatograms of blank serum and urine were cleaner than those obtained from classical solid-phase extraction or liquid extraction. The recoveries from these two polymeric cartridges were higher (95-102%) than those obtained by the two previous classical methods and the total time for extraction and solvent evaporation was also shorter (about 6-7 min). For methadone and benzodiazepine extraction, the use of acidic or alkaline buffer was not necessary.
He
Hua
H
Division of Analytical Chemistry, China Pharmaceutical University, Nanjing 210009, PR China.
Sun
Cheng
C
Wang
Xiao-Rong
XR
Pham-Huy
Chuong
C
Chikhi-Chorfi
Nassima
N
Galons
Hervé
H
Thevenin
Marc
M
Claude
Jean-Roger
JR
Warnet
Jean-Michel
JM
D000818:Animals; D001569:Benzodiazepines / Q000032:analysis* / Q000097:blood / Q000652:urine; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006801:Humans; D008691:Methadone / Q000032:analysis* / Q000097:blood / Q000652:urine; D011108:Polymers / Q000737:chemistry*; D011817:Rabbits; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D013237:Stereoisomerism
D011108:Polymers; D001569:Benzodiazepines; D008691:Methadone