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Marilyn A Huestis - One of the best experts on this subject based on the ideXlab platform.
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validation of a lc apci ms ms method for quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyraline emdp in infant plasma following protein precipitation
Journal of Chromatography B, 2007Co-Authors: Diaa M Shakleya, Lauren M Jansson, Marilyn A HuestisAbstract:Abstract A validated, quantitative LC–APCI-MS/MS method for methadone, EDDP and EMDP in 200-μL plasma is presented. Specimen preparation was limited to protein precipitation and centrifugation. Chromatographic separation was achieved on a Synergi Hydro-RP 80A (50 mm × 2.0 mm, 4 μm) column with gradient elution. The assay was linear from 1 to 500 ng/mL, with intra- and inter-assay accuracy ≥87.5% and intra- and inter-assay precision
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a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometric method for the quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyroline emdp in human breast milk
Journal of Analytical Toxicology, 2007Co-Authors: Robin E Choo, Lauren M Jansson, Karl B Scheidweiler, Marilyn A HuestisAbstract:This manuscript details a validated liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS-MS) method for the quantification of methadone and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyroline (EMDP) in 0.5 mL human breast milk. Limits of detection were 5 ng/mL for methadone and EDDP, and 10 ng/mL for EMDP. Linearity ranged from 10 to 500 ng/mL for all analytes. Breast milk is a complex biological fluid, necessitating several specimen preparation steps to separate methadone and metabolites from the lipophilic matrix. Recoveries were 66-97% following protein precipitation and solid-phase extraction with minimal matrix effect. Acceptable accuracy (89-101%) and precision (15-20% RSD) were achieved for all analytes. This is the first LC-APCI-MS-MS method for the sensitive and specific detection of methadone, EDDP, and EMDP in human breast milk. The method proved suitable for quantification of methadone and metabolites in breast milk of methadone-maintained opiate-dependent women.
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determination of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine 2 ethyl 5 methyl 3 3 diphenylpyraline and methadol in meconium by liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry
Journal of Chromatography B, 2005Co-Authors: Robin E Choo, Constance M Murphy, Hendree E Jones, Marilyn A HuestisAbstract:This paper details a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) method for the quantification of methadone, and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), 2-ethyl-5-methyl-3,3-diphenylpyraline (EMDP) and methadol in human meconium. Limits of detection (LOD) were determined to be 1.0 ng/g for methadone, EDDP and EMDP and 2.5 ng/g for methadol. The limits of quantitation (LOQ) for methadone, EDDP, EMDP were 5 and 25 ng/g for methadol. Linearity ranged from 5.0 to 500 ng/g. Following solid-phase extraction, no matrix effect was observed. This method proved to be suitable for the quantification of methadone, EDDP and EMDP and the semi-quantitation of methadol in meconium. Literature review revealed no other published LC-APCI-MS/MS method for the detection of methadone and its three main metabolites in meconium specimens.
Robin E Choo - One of the best experts on this subject based on the ideXlab platform.
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a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometric method for the quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyroline emdp in human breast milk
Journal of Analytical Toxicology, 2007Co-Authors: Robin E Choo, Lauren M Jansson, Karl B Scheidweiler, Marilyn A HuestisAbstract:This manuscript details a validated liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS-MS) method for the quantification of methadone and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyroline (EMDP) in 0.5 mL human breast milk. Limits of detection were 5 ng/mL for methadone and EDDP, and 10 ng/mL for EMDP. Linearity ranged from 10 to 500 ng/mL for all analytes. Breast milk is a complex biological fluid, necessitating several specimen preparation steps to separate methadone and metabolites from the lipophilic matrix. Recoveries were 66-97% following protein precipitation and solid-phase extraction with minimal matrix effect. Acceptable accuracy (89-101%) and precision (15-20% RSD) were achieved for all analytes. This is the first LC-APCI-MS-MS method for the sensitive and specific detection of methadone, EDDP, and EMDP in human breast milk. The method proved suitable for quantification of methadone and metabolites in breast milk of methadone-maintained opiate-dependent women.
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determination of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine 2 ethyl 5 methyl 3 3 diphenylpyraline and methadol in meconium by liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry
Journal of Chromatography B, 2005Co-Authors: Robin E Choo, Constance M Murphy, Hendree E Jones, Marilyn A HuestisAbstract:This paper details a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometry (LC-APCI-MS/MS) method for the quantification of methadone, and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), 2-ethyl-5-methyl-3,3-diphenylpyraline (EMDP) and methadol in human meconium. Limits of detection (LOD) were determined to be 1.0 ng/g for methadone, EDDP and EMDP and 2.5 ng/g for methadol. The limits of quantitation (LOQ) for methadone, EDDP, EMDP were 5 and 25 ng/g for methadol. Linearity ranged from 5.0 to 500 ng/g. Following solid-phase extraction, no matrix effect was observed. This method proved to be suitable for the quantification of methadone, EDDP and EMDP and the semi-quantitation of methadol in meconium. Literature review revealed no other published LC-APCI-MS/MS method for the detection of methadone and its three main metabolites in meconium specimens.
Karl B Scheidweiler - One of the best experts on this subject based on the ideXlab platform.
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a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometric method for the quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyroline emdp in human breast milk
Journal of Analytical Toxicology, 2007Co-Authors: Robin E Choo, Lauren M Jansson, Karl B Scheidweiler, Marilyn A HuestisAbstract:This manuscript details a validated liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS-MS) method for the quantification of methadone and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyroline (EMDP) in 0.5 mL human breast milk. Limits of detection were 5 ng/mL for methadone and EDDP, and 10 ng/mL for EMDP. Linearity ranged from 10 to 500 ng/mL for all analytes. Breast milk is a complex biological fluid, necessitating several specimen preparation steps to separate methadone and metabolites from the lipophilic matrix. Recoveries were 66-97% following protein precipitation and solid-phase extraction with minimal matrix effect. Acceptable accuracy (89-101%) and precision (15-20% RSD) were achieved for all analytes. This is the first LC-APCI-MS-MS method for the sensitive and specific detection of methadone, EDDP, and EMDP in human breast milk. The method proved suitable for quantification of methadone and metabolites in breast milk of methadone-maintained opiate-dependent women.
Lauren M Jansson - One of the best experts on this subject based on the ideXlab platform.
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validation of a lc apci ms ms method for quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyraline emdp in infant plasma following protein precipitation
Journal of Chromatography B, 2007Co-Authors: Diaa M Shakleya, Lauren M Jansson, Marilyn A HuestisAbstract:Abstract A validated, quantitative LC–APCI-MS/MS method for methadone, EDDP and EMDP in 200-μL plasma is presented. Specimen preparation was limited to protein precipitation and centrifugation. Chromatographic separation was achieved on a Synergi Hydro-RP 80A (50 mm × 2.0 mm, 4 μm) column with gradient elution. The assay was linear from 1 to 500 ng/mL, with intra- and inter-assay accuracy ≥87.5% and intra- and inter-assay precision
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a validated liquid chromatography atmospheric pressure chemical ionization tandem mass spectrometric method for the quantification of methadone 2 Ethylidene 1 5 dimethyl 3 3 diphenylpyrrolidine eddp and 2 ethyl 5 methyl 3 3 diphenylpyroline emdp in human breast milk
Journal of Analytical Toxicology, 2007Co-Authors: Robin E Choo, Lauren M Jansson, Karl B Scheidweiler, Marilyn A HuestisAbstract:This manuscript details a validated liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (LC-APCI-MS-MS) method for the quantification of methadone and its metabolites 2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyroline (EMDP) in 0.5 mL human breast milk. Limits of detection were 5 ng/mL for methadone and EDDP, and 10 ng/mL for EMDP. Linearity ranged from 10 to 500 ng/mL for all analytes. Breast milk is a complex biological fluid, necessitating several specimen preparation steps to separate methadone and metabolites from the lipophilic matrix. Recoveries were 66-97% following protein precipitation and solid-phase extraction with minimal matrix effect. Acceptable accuracy (89-101%) and precision (15-20% RSD) were achieved for all analytes. This is the first LC-APCI-MS-MS method for the sensitive and specific detection of methadone, EDDP, and EMDP in human breast milk. The method proved suitable for quantification of methadone and metabolites in breast milk of methadone-maintained opiate-dependent women.
Irving W Wainer - One of the best experts on this subject based on the ideXlab platform.
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determination of total and free concentrations of the enantiomers of methadone and its metabolite 2 Ethylidene 1 5 dimethyl 3 3 diphenyl pyrrolidine in human plasma by enantioselective liquid chromatography with mass spectrometric detection
Journal of Chromatography A, 2005Co-Authors: Maria Esther Rodriguezrosas, Juan G Medrano, David H Epstein, Eric T Moolchan, Kenzie L Preston, Irving W WainerAbstract:A sensitive enantioselective liquid chromatographic assay with mass spectrometric detection (LC-MS) has been validated for the determination of total and free plasma concentrations of (R)- and (S)-methadone (Met) and (R)- and (S)-2-Ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP, the primary metabolite of Met), using their respective deuterium-labeled compounds as internal standards [(R,S)-d3-Met and (R,S)-d3-EDDP]. For total drug determinations, 1 ml human plasma was extracted, using a cation-exchange solid-phase extraction cartridge; the eluate was evaporated, reconstituted in the mobile phase, and injected into the LC-MS system. The free fractions of Met and EDDP were determined, using 500 microl of plasma, which were placed in an ultrafiltration device and centrifuged at 2000 x g until 250 microl of filtrate was collected. The filtrate was extracted as described above and analyzed. Enantioselective separations were achieved using an alpha1-acid glycoprotein chiral stationary phase, a mobile phase composed of acetonitrile-ammonium acetate buffer [10 mM, pH 7.0] (18:82, v/v), a flow rate of 0.9 ml/min at 25 degrees C. Under these conditions, enantioselective separations were observed for Met (alpha = 1.30) and EDDP (alpha = 1.17) within 15 min. Met, EDDP, [2H3]-Met and [2H3]-EDDP were detected using selected ion monitoring at m/z 310.30, 278.20, 313.30, and 281.20, respectively. Linear relationships between peak height ratio and drug-enantiomer concentrations were obtained for Met in the range 1.0-300.0 ng/ml, and for EDDP from 0.1 to 25.0 ng/ml with correlation coefficients greater than 0.999, where the lower limit of quantification (LLOQ) was 1 ng/ml for Met and 0.1 ng/ml for EDDP. The relative standard deviation (R.S.D.) expressed as R.S.D. for the intra- and inter-day precision of the method were < 5.3% and the R.S.D. for accuracy was < 5.0%. The method was used to analyze plasma samples obtained from patients enrolled in a Met-maintenance program.