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Marilyn A Huestis - One of the best experts on this subject based on the ideXlab platform.
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A validated method for the determination of nicotine, cotinine, trans‐3′‐hydroxycotinine, and Norcotinine in human plasma using solid‐phase extraction and liquid chromatography‐atmospheric pressure chemical ionization‐mass spectrometry
Journal of Mass Spectrometry, 2020Co-Authors: Marilyn A HuestisAbstract:A liquid chromatographic-mass spectrometric method for the simultaneous determination of nicotine, cotinine, trans-3′-hydroxycotinine, and Norcotinine in human plasma was developed and validated. Analytes and deuterated internal standards were extracted from human plasma using solid-phase extraction and analyzed by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometric detection with selected ion monitoring (SIM). Limits of detection and quantification were 1.0 and 2.5 ng/ml, respectively, for all analytes. Linearity ranged from 2.5 to 500 ng/ml of human plasma using a weighting factor of 1/x; correlation coefficients for the calibration curves were > 0.99. Intra- and inter-assay precision and accuracy were < 15.0%. Recoveries were 108.2–110.8% nicotine, 95.8–108.7% cotinine, 90.5–99.5% trans-3′-hydroxycotinine, and 99.5–109.5% Norcotinine. The method was also partially validated in bovine serum, owing to the difficulty of obtaining nicotine-free human plasma for the preparation of calibrators and quality control (QC) samples. This method proved to be robust and accurate for the quantification of nicotine, cotinine, trans-3′-hydroxycotinine, and Norcotinine in human plasma collected in clinical studies of acute nicotine effects on brain activity and on the development of neonates of maternal smokers. Copyright © 2006 John Wiley & Sons, Ltd.
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simultaneous quantification of nicotine cotinine trans 3 hydroxycotinine Norcotinine and mecamylamine in human urine by liquid chromatography tandem mass spectrometry
Clinica Chimica Acta, 2012Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Marilyn A HuestisAbstract:Abstract Background Mecamylamine is a nicotine antagonist under investigation in combination with nicotine replacement for smoking treatment. Methods A simple, rapid and reliable liquid chromatography tandem mass spectrometry (LCMSMS) method was developed and validated for quantifying nicotine, cotinine, trans-3′-hydroxycotinine, Norcotinine and mecamylamine in human urine. Chromatography was performed on a Synergi PolarRP column with a gradient of 0.1% formic acid and 0.1% formic acid in acetonitrile at 0.25 ml/min with an 8-min total runtime. Analytes were monitored by positive mode electrospray ionization and multiple reaction monitoring mass spectrometry. Results Linear dynamic ranges were 1–500 ng/ml for nicotine and Norcotinine, 0.5–500 ng/ml for trans-3′-hydroxycotinine, 0.2–500 ng/ml for cotinine, and 0.1–100 ng/ml for mecamylamine; correlation coefficients were consistently greater than 0.99, and all calibrator concentrations were within 20% of target. Extensive endogenous and exogenous interferences were evaluated. At 3 concentrations spanning the linear dynamic range of the assay, mean extraction efficiencies from urine were 55.1–109.1% with analytical recovery (bias) 82.0–118.7% and total imprecision of 0.7–9.1%. Analytes were stable for 24 h at room temperature, 72 h at 4 °C, 72 h in autosampler at 15 °C and after three freeze/thaw cycles. Conclusion This method is useful for monitoring mecamylamine, nicotine and nicotine metabolites in smoking cessation and other clinical nicotine research.
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Simultaneous quantification of nicotine, cotinine, trans-3'-hydroxycotinine, Norcotinine and mecamylamine in human urine by liquid chromatography-tandem mass spectrometry.
Clinica chimica acta; international journal of clinical chemistry, 2012Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Marilyn A HuestisAbstract:Mecamylamine is a nicotine antagonist under investigation in combination with nicotine replacement for smoking treatment. A simple, rapid and reliable liquid chromatography tandem mass spectrometry (LCMSMS) method was developed and validated for quantifying nicotine, cotinine, trans-3'-hydroxycotinine, Norcotinine and mecamylamine in human urine. Chromatography was performed on a Synergi PolarRP column with a gradient of 0.1% formic acid and 0.1% formic acid in acetonitrile at 0.25 ml/min with an 8-min total runtime. Analytes were monitored by positive mode electrospray ionization and multiple reaction monitoring mass spectrometry. Linear dynamic ranges were 1-500 ng/ml for nicotine and Norcotinine, 0.5-500 ng/ml for trans-3'-hydroxycotinine, 0.2-500 ng/ml for cotinine, and 0.1-100 ng/ml for mecamylamine; correlation coefficients were consistently greater than 0.99, and all calibrator concentrations were within 20% of target. Extensive endogenous and exogenous interferences were evaluated. At 3 concentrations spanning the linear dynamic range of the assay, mean extraction efficiencies from urine were 55.1-109.1% with analytical recovery (bias) 82.0-118.7% and total imprecision of 0.7-9.1%. Analytes were stable for 24h at room temperature, 72 h at 4 °C, 72 h in autosampler at 15 °C and after three freeze/thaw cycles. This method is useful for monitoring mecamylamine, nicotine and nicotine metabolites in smoking cessation and other clinical nicotine research. Published by Elsevier B.V.
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Oral fluid nicotine markers to assess smoking status and recency of use.
Therapeutic Drug Monitoring, 2011Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Gina F Marrone, Edward G. Singleton, Stephen J. Heishman, Marilyn A HuestisAbstract:Oral fluid collection is non-invasive and easily observed making it an attractive matrix for objectively determining smoking status. Despite large inter-subject variability, cotinine oral fluid concentrations correlate with cigarettes smoked per day (CPD). Few studies, however, assessed nicotine markers in oral fluid other than cotinine; other markers might improve smoking status assessment and/or time of last cigarette. Materials and Methods Smoking histories and oral fluid specimens were collected from non-treatment-seeking light (1–10 CPD) and heavy smokers (>10 CPD), and from environmentally exposed and nonexposed nonsmokers who provided written informed consent for this Institutional Review Board-approved study. Nicotine, cotinine, hydroxycotinine (OH-cotinine) and Norcotinine oral fluid concentrations were quantified via liquid chromatography tandem mass spectrometry (LCMSMS).
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Optimization and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of nicotine, cotinine, trans-3′-hydroxycotinine and Norcotinine in human oral fluid
Analytical and Bioanalytical Chemistry, 2009Co-Authors: Diaa M. Shakleya, Marilyn A HuestisAbstract:An analytical procedure was developed and validated for the simultaneous identification and quantification of nicotine, cotinine, trans -3′-hydroxycotinine, and Norcotinine in 0.5 mL of human oral fluid collected with the Quantisal™ oral fluid collection device. Solid phase extraction and liquid chromatography-tandem mass spectrometry with multiple reaction monitoring were utilized. Endogenous and exogenous interferences were extensively evaluated. Limits of quantification were empirically identified by decreasing analyte concentrations. Linearity was from 1 to 2,000 ng/mL for nicotine and Norcotinine, 0.5 to 2,000 ng/mL for trans -3′-hydroxycotinine, and 0.2 to 2,000 ng/mL for cotinine. Correlation coefficients for calibration curves were >0.99 and analytes quantified within ±13% of target at all calibrator concentrations. Suitable analytical recovery (>91%) was achieved with extraction efficiencies >56% and matrix effects
Diaa M. Shakleya - One of the best experts on this subject based on the ideXlab platform.
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simultaneous quantification of nicotine cotinine trans 3 hydroxycotinine Norcotinine and mecamylamine in human urine by liquid chromatography tandem mass spectrometry
Clinica Chimica Acta, 2012Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Marilyn A HuestisAbstract:Abstract Background Mecamylamine is a nicotine antagonist under investigation in combination with nicotine replacement for smoking treatment. Methods A simple, rapid and reliable liquid chromatography tandem mass spectrometry (LCMSMS) method was developed and validated for quantifying nicotine, cotinine, trans-3′-hydroxycotinine, Norcotinine and mecamylamine in human urine. Chromatography was performed on a Synergi PolarRP column with a gradient of 0.1% formic acid and 0.1% formic acid in acetonitrile at 0.25 ml/min with an 8-min total runtime. Analytes were monitored by positive mode electrospray ionization and multiple reaction monitoring mass spectrometry. Results Linear dynamic ranges were 1–500 ng/ml for nicotine and Norcotinine, 0.5–500 ng/ml for trans-3′-hydroxycotinine, 0.2–500 ng/ml for cotinine, and 0.1–100 ng/ml for mecamylamine; correlation coefficients were consistently greater than 0.99, and all calibrator concentrations were within 20% of target. Extensive endogenous and exogenous interferences were evaluated. At 3 concentrations spanning the linear dynamic range of the assay, mean extraction efficiencies from urine were 55.1–109.1% with analytical recovery (bias) 82.0–118.7% and total imprecision of 0.7–9.1%. Analytes were stable for 24 h at room temperature, 72 h at 4 °C, 72 h in autosampler at 15 °C and after three freeze/thaw cycles. Conclusion This method is useful for monitoring mecamylamine, nicotine and nicotine metabolites in smoking cessation and other clinical nicotine research.
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Simultaneous quantification of nicotine, cotinine, trans-3'-hydroxycotinine, Norcotinine and mecamylamine in human urine by liquid chromatography-tandem mass spectrometry.
Clinica chimica acta; international journal of clinical chemistry, 2012Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Marilyn A HuestisAbstract:Mecamylamine is a nicotine antagonist under investigation in combination with nicotine replacement for smoking treatment. A simple, rapid and reliable liquid chromatography tandem mass spectrometry (LCMSMS) method was developed and validated for quantifying nicotine, cotinine, trans-3'-hydroxycotinine, Norcotinine and mecamylamine in human urine. Chromatography was performed on a Synergi PolarRP column with a gradient of 0.1% formic acid and 0.1% formic acid in acetonitrile at 0.25 ml/min with an 8-min total runtime. Analytes were monitored by positive mode electrospray ionization and multiple reaction monitoring mass spectrometry. Linear dynamic ranges were 1-500 ng/ml for nicotine and Norcotinine, 0.5-500 ng/ml for trans-3'-hydroxycotinine, 0.2-500 ng/ml for cotinine, and 0.1-100 ng/ml for mecamylamine; correlation coefficients were consistently greater than 0.99, and all calibrator concentrations were within 20% of target. Extensive endogenous and exogenous interferences were evaluated. At 3 concentrations spanning the linear dynamic range of the assay, mean extraction efficiencies from urine were 55.1-109.1% with analytical recovery (bias) 82.0-118.7% and total imprecision of 0.7-9.1%. Analytes were stable for 24h at room temperature, 72 h at 4 °C, 72 h in autosampler at 15 °C and after three freeze/thaw cycles. This method is useful for monitoring mecamylamine, nicotine and nicotine metabolites in smoking cessation and other clinical nicotine research. Published by Elsevier B.V.
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Oral fluid nicotine markers to assess smoking status and recency of use.
Therapeutic Drug Monitoring, 2011Co-Authors: Karl B Scheidweiler, Diaa M. Shakleya, Gina F Marrone, Edward G. Singleton, Stephen J. Heishman, Marilyn A HuestisAbstract:Oral fluid collection is non-invasive and easily observed making it an attractive matrix for objectively determining smoking status. Despite large inter-subject variability, cotinine oral fluid concentrations correlate with cigarettes smoked per day (CPD). Few studies, however, assessed nicotine markers in oral fluid other than cotinine; other markers might improve smoking status assessment and/or time of last cigarette. Materials and Methods Smoking histories and oral fluid specimens were collected from non-treatment-seeking light (1–10 CPD) and heavy smokers (>10 CPD), and from environmentally exposed and nonexposed nonsmokers who provided written informed consent for this Institutional Review Board-approved study. Nicotine, cotinine, hydroxycotinine (OH-cotinine) and Norcotinine oral fluid concentrations were quantified via liquid chromatography tandem mass spectrometry (LCMSMS).
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Optimization and validation of a liquid chromatography-tandem mass spectrometry method for the simultaneous quantification of nicotine, cotinine, trans-3′-hydroxycotinine and Norcotinine in human oral fluid
Analytical and Bioanalytical Chemistry, 2009Co-Authors: Diaa M. Shakleya, Marilyn A HuestisAbstract:An analytical procedure was developed and validated for the simultaneous identification and quantification of nicotine, cotinine, trans -3′-hydroxycotinine, and Norcotinine in 0.5 mL of human oral fluid collected with the Quantisal™ oral fluid collection device. Solid phase extraction and liquid chromatography-tandem mass spectrometry with multiple reaction monitoring were utilized. Endogenous and exogenous interferences were extensively evaluated. Limits of quantification were empirically identified by decreasing analyte concentrations. Linearity was from 1 to 2,000 ng/mL for nicotine and Norcotinine, 0.5 to 2,000 ng/mL for trans -3′-hydroxycotinine, and 0.2 to 2,000 ng/mL for cotinine. Correlation coefficients for calibration curves were >0.99 and analytes quantified within ±13% of target at all calibrator concentrations. Suitable analytical recovery (>91%) was achieved with extraction efficiencies >56% and matrix effects
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simultaneous and sensitive measurement of nicotine cotinine trans 3 hydroxycotinine and Norcotinine in human plasma by liquid chromatography tandem mass spectrometry
Journal of Chromatography B, 2009Co-Authors: Diaa M. Shakleya, Marilyn A HuestisAbstract:Abstract An LC-MS/MS method for the simultaneous quantification of nicotine, cotinine, trans-3′-hydroxycotinine and Norcotinine in human plasma was developed and fully validated. Potential endogenous and exogenous interferences were extensively evaluated and limits of quantification were determined by decreasing analyte concentration. Analytical ranges were 1–500 ng/mL for nicotine and cotinine, 5–500 ng/mL for trans-3′-hydroxycotinine and Norcotinine. Mean intra- and inter-assay analytical recoveries were between 101.9 and 116.8%, and intra- and inter-assay imprecision were less than 11% RSD for all analytes: parameters were evaluated at three different concentrations across the linear range of the assay. Extraction efficiency was ≥70% for all analytes. This validated method is useful for the determination of nicotine and metabolites in human plasma to support research on the role of nicotine biomarkers on neuronal systems mediating cognitive and affective processes and to differentiate active, passive and environmental exposure.
Teresa R Gray - One of the best experts on this subject based on the ideXlab platform.
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Meconium Nicotine and Metabolites by Liquid Chromatography–Tandem Mass Spectrometry: Differentiation of Passive and Nonexposure and Correlation with Neonatal Outcome Measures
Clinical Chemistry, 2008Co-Authors: Teresa R Gray, Diaa M. Shakleya, Raquel Magri, Marilyn A HuestisAbstract:Background: Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes’ concentrations with neonatal outcomes is unexplored. Our objectives were to quantify nicotine, cotinine, trans -3′-hydroxycotinine (OH-cotinine), nornicotine, Norcotinine, and glucuronide concentrations in meconium, identify the best biomarkers of in utero tobacco exposure, compare meconium concentrations of tobacco-exposed and nonexposed neonates, and investigate concentration-outcome relationships. Methods: We quantified concentrations of nicotine and 4 metabolites with and without hydrolysis simultaneously in meconium from tobacco-exposed and nonexposed neonates by liquid chromatography-tandem mass spectrometry. We compared meconium concentrations to birth weight, length, head circumference, gestational age, and 1- and 5-min Apgar scores. Results: Nicotine, cotinine, and OH-cotinine were the most prevalent and abundant meconium tobacco biomarkers and were found in higher concentrations in tobacco-exposed neonates. Whereas cotinine and OH-cotinine are glucuronide bound, performing the lengthy and costly enzymatic hydrolysis identified only 1 additional positive specimen. Unconjugated nicotine, cotinine, or OH-cotinine meconium concentration >10 ng/g most accurately discriminated active from passive and nonexposed neonates. There was no significant correlation between quantitative nicotine and metabolite meconium results and neonatal outcomes, although presence of a nicotine biomarker predicted decreased head circumference. Conclusions: Unconjugated nicotine, cotinine, and OH-cotinine should be analyzed in meconium to detect in utero tobacco exposure, as approximately 25% of positive specimens did not contain cotinine. Immunoassay testing monitoring cotinine only would underestimate the prevalence of prenatal tobacco exposure.
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quantification of nicotine cotinine trans 3 hydroxycotinine nornicotine and Norcotinine in human meconium by liquid chromatography tandem mass spectrometry
Journal of Chromatography B, 2008Co-Authors: Teresa R Gray, Diaa M. Shakleya, Marilyn A HuestisAbstract:Abstract There are no analytical methods that simultaneously quantify nicotine, cotinine, trans -3′-hydroxycotinine, nornicotine and Norcotinine in human meconium. Such a method could improve identification of in utero tobacco exposure, determine if maternal dose–meconium concentration relationships exist, and whether nicotine meconium concentrations predict neonatal outcomes. The first liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry method for simultaneous quantification of these analytes in meconium was developed and validated. Specimen preparation included homogenization, enzyme hydrolysis and solid phase extraction. The linear range was 1.25 or 5–500 ng/g. Method applicability was evaluated with meconium collected from an in utero tobacco exposed infant.
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Quantification of nicotine, cotinine, trans-3'-hydroxycotinine, nornicotine and Norcotinine in human meconium by liquid chromatography/tandem mass spectrometry.
Journal of Chromatography B, 2008Co-Authors: Teresa R Gray, Diaa M. Shakleya, Marilyn A HuestisAbstract:Abstract There are no analytical methods that simultaneously quantify nicotine, cotinine, trans -3′-hydroxycotinine, nornicotine and Norcotinine in human meconium. Such a method could improve identification of in utero tobacco exposure, determine if maternal dose–meconium concentration relationships exist, and whether nicotine meconium concentrations predict neonatal outcomes. The first liquid chromatography/atmospheric pressure chemical ionization tandem mass spectrometry method for simultaneous quantification of these analytes in meconium was developed and validated. Specimen preparation included homogenization, enzyme hydrolysis and solid phase extraction. The linear range was 1.25 or 5–500 ng/g. Method applicability was evaluated with meconium collected from an in utero tobacco exposed infant.
Diana G. Wilkins - One of the best experts on this subject based on the ideXlab platform.
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Simultaneous quantification of nicotine and metabolites in rat brain by liquid chromatography-tandem mass spectrometry.
Journal of Chromatography B, 2011Co-Authors: Paula L. Vieira-brock, Eleanor I. Miller, Shannon M. Nielsen, Annette E. Fleckenstein, Diana G. WilkinsAbstract:Abstract A liquid chromatography–tandem mass spectrometry (LC–MS/MS) method for simultaneous quantification of nicotine (NIC), cotinine (COT), nornicotine (NNIC), Norcotinine (NCOT), nicotine-N-β- d -glucuronide (NIC GLUC), cotinine-N-β- d -glucuronide (COT GLUC), nicotine-1′-oxide (NNO), cotinine-N-oxide (CNO), trans-3′-hydroxycotinine (3-HC), anabasine (AB) and anatabine (AT) was modified and validated for quantification of these selected analytes in rat brain tissue. This analytical method provides support for preclinical NIC pharmacokinetic and toxicological studies after controlled dosing protocols. After brain homogenization and solid-phase extraction, target analytes and corresponding deuterated internal standards were chromatographically separated on a Discovery® HS F5 HPLC column with gradient elution and analyzed by LC–MS/MS in positive electrospray ionization (ESI) mode with multiple reaction monitoring (MRM) data acquisition. Method linearity was assessed and calibration curves were determined over the following ranges: 0.1–7.5 ng/mg for NIC, COT GLUC and AB; and 0.025–7.5 ng/mg for COT, NNIC, NCOT, NIC GLUC, NNO, CNO, 3-HC and AT (R2 ≥ 0.99 for all analytes). Extraction recoveries ranged from 64% to 115%, LC–MS/MS matrix effects were ≤21%, and overall process efficiency ranged from 57% to 93% at low and high quality control concentrations. Intra- and inter-assay imprecisions and accuracy for all analytes were ≤12.9% and ≥86%, respectively. The method was successfully applied to quantification of NIC and metabolites in the brain of post-natal day 90 rats that were sacrificed 2-h after a single 0.8 mg/kg s.c. administration of (−)NIC. In these tissues, striatal concentrations were 204.8 ± 49.4, 138.2 ± 14.2 and 36.1 ± 6.1 pg/mg of NIC, COT and NNIC, respectively. Concentrations of NIC, COT and NNIC in the remaining whole brain (RWhB) were 183.3 ± 68.0, 130.0 ± 14.1 and 46.7 ± 10.3 pg/mg, respectively. Quantification of these same analytes in plasma was also performed by a previously validated method. NIC, COT, NNIC, NCOT, NNO and CNO were detected in plasma with concentrations comparable to those reported in previous studies. However, and in contrast to brain tissues, COT concentrations in plasma were significantly higher than were those of NIC (194.6 ± 18.6 ng/mL versus 52.7 ± 12.9 ng/mL). Taken together, these results demonstrate that a sensitive and selective method has been developed for the determination of NIC biomarkers in rat brain.
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Identification and Quantification of Nicotine Biomarkers in Human Oral Fluid from Individuals Receiving Low-Dose Transdermal Nicotine: A Preliminary Study
Journal of Analytical Toxicology, 2010Co-Authors: Eleanor I. Miller, Hye Ryun K Norris, Douglas E. Rollins, Stephen T. Tiffany, Christine Moore, Michael Vincent, Alpana Agrawal, Diana G. WilkinsAbstract:: The objective of this preliminary study was to identify and quantify potential nicotine (NIC) biomarkers in post-exposure oral fluid samples collected from 10 NIC-abstinent human participants administered 7 mg transdermal NIC using liquid chromatography-tandem mass spectrometry (LC-MS-MS). Oral fluid samples were collected prior to NIC patch application and at 0.5 and 0.75 h after patch removal using the Quantisal() oral fluid collection device. The validated LC-MS-MS analyte panel included nicotine-Nbeta-D-glucuronide, cotinine-N-oxide, trans-3-hydroxycotinine, Norcotinine, trans-nicotine-1'-N-oxide, cotinine (COT), nornicotine, NIC, anatabine, anabasine, and cotinine-N-beta-D-glucuronide. Analytes and corresponding deuterated internal standards were extracted by solid-phase extraction. NIC and COT concentrations were quantifiable in oral fluid samples collected from 6 of the 10 participants 0.5 h after patch removal and in oral fluid samples collected from 7 of the 10 participants 0.75 h after patch removal. Based on the mean NIC and COT concentrations in oral fluid and plasma for the participants with both quantifiable NIC and COT at the 0.5 and 0.75 h collection times, the oral fluid-plasma ratio was 6.4 for NIC and 3.3 for COT. An ELISA procedure was also validated and successfully applied as a screening tool for these oral fluid samples in conjunction with LC-MS-MS confirmation. An ELISA cut-off concentration of 5.0 ng/mL provided excellent sensitivity for discrimination of COT-positive post-exposure oral fluid samples collected after low-level transdermal NIC exposure and oral fluid samples collected prior to patch application.
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A novel validated procedure for the determination of nicotine, eight nicotine metabolites and two minor tobacco alkaloids in human plasma or urine by solid-phase extraction coupled with liquid chromatography-electrospray ionization-tandem mass spectr
Journal of Chromatography B, 2010Co-Authors: Eleanor I. Miller, Hye Ryun K Norris, Douglas E. Rollins, Stephen T. Tiffany, Diana G. WilkinsAbstract:Abstract A novel validated liquid chromatography–tandem mass spectrometry (LC–MS/MS) procedure was developed and fully validated for the simultaneous determination of nicotine-N-β- d -glucuronide, cotinine-N-oxide, trans -3-hydroxycotinine, Norcotinine, trans -nicotine-1′-oxide, cotinine, nornicotine, nicotine, anatabine, anabasine and cotinine-N-β- d -glucuronide in human plasma or urine. Target analytes and corresponding deuterated internal standards were extracted by solid-phase extraction and analyzed by LC–MS/MS with electrospray ionization (ESI) using multiple reaction monitoring (MRM) data acquisition. Calibration curves were linear over the selected concentration ranges for each analyte, with calculated coefficients of determination ( R 2 ) of greater than 0.99. The total extraction recovery (%) was concentration dependent and ranged between 52–88% in plasma and 51–118% in urine. The limits of quantification for all analytes in plasma and urine were 1.0 ng/mL and 2.5 ng/mL, respectively, with the exception of cotinine-N-β- d -glucuronide, which was 50 ng/mL. Intra-day and inter-day imprecision were ≤14% and ≤17%, respectively. Matrix effect (%) was sufficiently minimized to ≤19% for both matrices using the described sample preparation and extraction methods. The target analytes were stable in both matrices for at least 3 freeze–thaw cycles, 24 h at room temperature, 24 h in the refrigerator (4 °C) and 1 week in the freezer (−20 °C). Reconstituted plasma and urine extracts were stable for at least 72 h storage in the liquid chromatography autosampler at 4 °C. The plasma procedure has been successfully applied in the quantitative determination of selected analytes in samples collected from nicotine-abstinent human participants as part of a pharmacokinetic study investigating biomarkers of nicotine use in plasma following controlled low dose (7 mg) transdermal nicotine delivery. Nicotine, cotinine, trans -3-hydroxycotinine and trans-nicotine-1′-oxide were detected in the particular sample presented herein. The urine procedure has been used to facilitate the monitoring of unauthorized tobacco use by clinical study participants at the time of physical examination (before enrollment) and on the pharmacokinetic study day.
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A novel validated procedure for the determination of nicotine, eight nicotine metabolites and two minor tobacco alkaloids in human plasma or urine by solid-phase extraction coupled with liquid chromatography-electrospray ionization-tandem mass spectr
Journal of chromatography. B Analytical technologies in the biomedical and life sciences, 2009Co-Authors: Eleanor I. Miller, Hye Ryun K Norris, Douglas E. Rollins, Stephen T. Tiffany, Diana G. WilkinsAbstract:A novel validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) procedure was developed and fully validated for the simultaneous determination of nicotine-N-beta-D-glucuronide, cotinine-N-oxide, trans-3-hydroxycotinine, Norcotinine, trans-nicotine-1'-oxide, cotinine, nornicotine, nicotine, anatabine, anabasine and cotinine-N-beta-D-glucuronide in human plasma or urine. Target analytes and corresponding deuterated internal standards were extracted by solid-phase extraction and analyzed by LC-MS/MS with electrospray ionization (ESI) using multiple reaction monitoring (MRM) data acquisition. Calibration curves were linear over the selected concentration ranges for each analyte, with calculated coefficients of determination (R(2)) of greater than 0.99. The total extraction recovery (%) was concentration dependent and ranged between 52-88% in plasma and 51-118% in urine. The limits of quantification for all analytes in plasma and urine were 1.0 ng/mL and 2.5 ng/mL, respectively, with the exception of cotinine-N-beta-D-glucuronide, which was 50 ng/mL. Intra-day and inter-day imprecision were < or = 14% and < or = 17%, respectively. Matrix effect (%) was sufficiently minimized to < or = 19% for both matrices using the described sample preparation and extraction methods. The target analytes were stable in both matrices for at least 3 freeze-thaw cycles, 24 h at room temperature, 24 h in the refrigerator (4 degrees C) and 1 week in the freezer (-20 degrees C). Reconstituted plasma and urine extracts were stable for at least 72 h storage in the liquid chromatography autosampler at 4 degrees C. The plasma procedure has been successfully applied in the quantitative determination of selected analytes in samples collected from nicotine-abstinent human participants as part of a pharmacokinetic study investigating biomarkers of nicotine use in plasma following controlled low dose (7 mg) transdermal nicotine delivery. Nicotine, cotinine, trans-3-hydroxycotinine and trans-nicotine-1'-oxide were detected in the particular sample presented herein. The urine procedure has been used to facilitate the monitoring of unauthorized tobacco use by clinical study participants at the time of physical examination (before enrollment) and on the pharmacokinetic study day.
Linda P Dwoskin - One of the best experts on this subject based on the ideXlab platform.
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Residence Times and Half-Lives of Nicotine Metabolites in Rat Brain after Acute Peripheral Administration of [2′-14C]Nicotine
Drug Metabolism and Disposition, 1999Co-Authors: Omar A. Ghosheh, Linda P Dwoskin, Wen-kui Li, Peter A CrooksAbstract:The residence times of nicotine and its metabolites in rat brain after acute peripheral nicotine administration were determined. We hypothesize that nicotine metabolites will reach pharmacologically significant concentrations in brain. Cotinine, nornicotine, and Norcotinine were structurally identified by dual label radiochemical and gas chromatography-mass spectrometric analysis as biotransformation products of nicotine present in rat brain after s.c. injection of S (−)-nicotine. Two unidentified minor metabolites were also detected in brain. The half-lives in brain of nicotine metabolites were determined after a single s.c. injection of [2′- 14 C]-(±)nicotine (0.8 mg/kg) and analysis of radiolabeled metabolites by high pressure-liquid radiochromatography. The brain half-lives of nicotine, cotinine, and nornicotine were 52, 333, and 166 min, respectively. Peak brain concentrations of nicotine metabolites were 300, 70, and 7 nM for cotinine, nornicotine, and Norcotinine, respectively. Even with potential accumulation of cotinine in brain after chronic nicotine administration, it is likely that the brain concentration of cotinine will be insufficient to produce neuropharmacological effects resulting from activation of nicotinic receptors to induce dopamine release. Conversely, the concentration of nornicotine in brain after acute nicotine approaches the range found to be neuropharmacologically active. It is likely that nornicotine will accumulate in brain on chronic nicotine administration based on the brain half-life of this metabolite. Importantly, nornicotine is also a major alkaloidal component of tobacco. Thus, as a consequence of tobacco use, alkaloidal and metabolically formed nornicotine may reach concentrations in brain sufficient to produce pharmacological effects.
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metabolites of nicotine in rat brain after peripheral nicotine administration cotinine nornicotine and Norcotinine
Drug Metabolism and Disposition, 1997Co-Authors: Peter A Crooks, Min Li, Linda P DwoskinAbstract:The time course of nicotine metabolite appearance in brain from 5 min–18 hr after subcutaneous administration of S -(−)-[ 3 H- N -methyl]nicotine was determined. Results demonstrated that metabolite appearance in brain was greatest at 4 hr postadministration, whereas levels of nicotine were greatly diminished at this time point. For determination of N -demethylated metabolites, (±)-[2′- 14 C]nicotine was administered subcutaneously to rats, and the presence of nicotine and nicotine metabolites in brain supernatant was determined 4 hr postadministration. Using high-performance liquid radiochromatographic analysis, nicotine and three nicotine metabolites (cotinine, nornicotine, and Norcotinine) were identified in brain, together with a fourth minor, unidentified metabolite. After subcutaneous administration of S -(−)-[G- 3 H]cotinine, significant amounts of cotinine were found in brain over an 18-hr postadministration period; however, no cotinine metabolites were detected. Therefore, cotinine is able to pass the blood-brain barrier and access the central nervous system, but is not biotransformed in brain. Thus, this is the first report of Norcotinine as a central nervous system nicotine metabolite. Data indicate that Norcotinine detected in brain after peripheral nicotine administration most likely originates from 5′-C-oxidation of brain nornicotine, rather than from N -demethylation of cotinine, as occurs peripherally. Because peripheral biotransformation of nicotine to nornicotine is a minor pathway, the relatively high levels of nornicotine found in brain after peripheral nicotine administration suggest that nornicotine is formed via oxidative N -demethylation of nicotine locally in brain. Nornicotine is pharmacologically active; thus, its presence in brain after peripheral nicotine administration indicates that nornicotine may contribute to the neuropharmacological effects of nicotine and tobacco use.
