Determination of methadone, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine and alprazolam in human plasma by liquid chromatography-electrospray ionization mass spectrometry.
A fast liquid chromatographic assay with mass spectrometric detection (LC/MS) has been developed and validated for the simultaneous determination of methadone (MT), its primary metabolite, 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and alprazolam, in human plasma. The extraction procedure was performed with automatic solid phase extraction, and the compounds were separated with a Sunfire column using a gradient mode. Deuterated analogues for all of the analytes of interest were used for quantitation. Limits of detection (LOD) were established between 0.5 and 1 ng/ml. Linearity was obtained over a range of 2-2,000 ng/ml with an average correlation coefficient (R(2)) of >0.99. Intra- and inter-batch coefficients of variation and relative mean errors were less than 10% for all analytes and concentrations. The recoveries were higher than 50.0% in all cases. The method proved to be suitable for evaluation of plasma obtained from patients enrolled in a MT-maintenance program who are frequently treated with alprazolam as a sedative.
Quintela
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Forensic Toxicology Service, Institute of Legal Medicine, University of Santiago de Compostela, Spain.
López
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Bermejo
A M
AM
López-Rivadulla
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M
D000525:Alprazolam / Q000097:blood*; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D006801:Humans; D008691:Methadone / Q000097:blood*; D011759:Pyrrolidines / Q000097:blood*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
D011759:Pyrrolidines; D008691:Methadone; D000525:Alprazolam; C010724:2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine