Ketamine is an anaesthetic drug, which since 1980s has spread also as an abusedpsychoactive substance. Because of its stimulant and dissociative effects, its monitoring is valuable,particularly for traffic and workplace safety. Traditionally available as racemic mixture, ketaminehas recently become available in the form of the single S-enantiomer, since it shows a higheranaesthetic potency associated with faster post-anaesthetic recovery time [1]. Such differentpharmacodynamic behaviour of the two enantiomers implies the need for a chiral method in theanalysis of biological matrices; however, most available analytical methods are not enantioselective[2-5]. On this basis, and considering the excellent chiral resolution power of CE, the aim of thepresent work was to develop a capillary zone electrophoresis (CZE) method for the enantioselectiveseparation of ketamine and its major metabolite, norketamine, in hair specimens. In comparisonwith biological fluids, hair analysis permits to investigate a larger time-window, also offeringgreater sample stability under a wide range of ambient conditions. In optimised conditions, acomplete separation of both racemic ketamine and norketamine in the respective enantiomers wasobtained in less than 10 minutes. Limit of detection (LOD) and limit of quantification (LOQ) were0.15 ng/mg and 0.50 ng/mg, respectively. Using a simple liquid-liquid extraction, percent recoveryof all four enantiomers varied from 49% to 91%. Matrix effect was also studied on spiked hairsamples providing values ranging from 63% to 119%. Linearity was estimated using a calibrationcurve consisting of five concentration levels (0.5-8.0 ng/mg); the regression coefficients (R2) ofweighted (1/x2) linear regression were all >0.988. The proposed method proved suitable for theanalysis of ketamine and norketamine in hair samples collected from ketamine abusers in order toinvestigate its chronic abuse and to discriminate between the type of drug taken by the individual,either single enantiomer or racemic drug.References:[1] A. Pai, M. Heining. Ketamine. Cont. Ed. in Anaesthesia, Critical Care & Pain, 7 (2007) 59-63.[2] Y.H. Lin, J.H. Li, W.K. Ko, S.M. Wu. Direct and sensitive analysis of methamphetamine,ketamine, morphine and codeine in human urine by cation-selective exhaustive injection andsweeping micellar electrokinetic chromatography. J. Chrom. A, 1130 (2006) 281-286[3] Y.H. Ho, C.C. Wang, Y.T. Hsiao, W.K. Ko, S.M. Wu. Analysis of ten abused drugs in urine bylarge volume sample stacking-sweeping capillary electrophoresis with an experimental designstrategy. J. Chrom. A, 1295 (2013) 136-141[4] D. Favretto, S. Vogliardi, G. Stocchero, A. Nalesso, M. Tucci, C. Terranova, S. D. Ferrara.Determination of ketamine and norketamine in hair by micropulverized extraction and liquidchromatography-high resolution mass spectrometry, For. Science Int., 226 (2013) 88-93[5] Y.H. Lin, M.R. Lee, R.J. Lee, W.K. Ko, S.M. Wu. Hair analysis for methamphetamine,ketamine, morphine and codeine by cation-selective exhaustive inject

Chiral determination of ketamine and norketamine by capillary electrophoresis in hair specimens, as a tool to investigate histories of abuse

Porpiglia, Nadia Maria;Musile, Giacomo;BORTOLOTTI, Federica;DE PALO, Elio Franco;TAGLIARO, Franco
2015-01-01

Abstract

Ketamine is an anaesthetic drug, which since 1980s has spread also as an abusedpsychoactive substance. Because of its stimulant and dissociative effects, its monitoring is valuable,particularly for traffic and workplace safety. Traditionally available as racemic mixture, ketaminehas recently become available in the form of the single S-enantiomer, since it shows a higheranaesthetic potency associated with faster post-anaesthetic recovery time [1]. Such differentpharmacodynamic behaviour of the two enantiomers implies the need for a chiral method in theanalysis of biological matrices; however, most available analytical methods are not enantioselective[2-5]. On this basis, and considering the excellent chiral resolution power of CE, the aim of thepresent work was to develop a capillary zone electrophoresis (CZE) method for the enantioselectiveseparation of ketamine and its major metabolite, norketamine, in hair specimens. In comparisonwith biological fluids, hair analysis permits to investigate a larger time-window, also offeringgreater sample stability under a wide range of ambient conditions. In optimised conditions, acomplete separation of both racemic ketamine and norketamine in the respective enantiomers wasobtained in less than 10 minutes. Limit of detection (LOD) and limit of quantification (LOQ) were0.15 ng/mg and 0.50 ng/mg, respectively. Using a simple liquid-liquid extraction, percent recoveryof all four enantiomers varied from 49% to 91%. Matrix effect was also studied on spiked hairsamples providing values ranging from 63% to 119%. Linearity was estimated using a calibrationcurve consisting of five concentration levels (0.5-8.0 ng/mg); the regression coefficients (R2) ofweighted (1/x2) linear regression were all >0.988. The proposed method proved suitable for theanalysis of ketamine and norketamine in hair samples collected from ketamine abusers in order toinvestigate its chronic abuse and to discriminate between the type of drug taken by the individual,either single enantiomer or racemic drug.References:[1] A. Pai, M. Heining. Ketamine. Cont. Ed. in Anaesthesia, Critical Care & Pain, 7 (2007) 59-63.[2] Y.H. Lin, J.H. Li, W.K. Ko, S.M. Wu. Direct and sensitive analysis of methamphetamine,ketamine, morphine and codeine in human urine by cation-selective exhaustive injection andsweeping micellar electrokinetic chromatography. J. Chrom. A, 1130 (2006) 281-286[3] Y.H. Ho, C.C. Wang, Y.T. Hsiao, W.K. Ko, S.M. Wu. Analysis of ten abused drugs in urine bylarge volume sample stacking-sweeping capillary electrophoresis with an experimental designstrategy. J. Chrom. A, 1295 (2013) 136-141[4] D. Favretto, S. Vogliardi, G. Stocchero, A. Nalesso, M. Tucci, C. Terranova, S. D. Ferrara.Determination of ketamine and norketamine in hair by micropulverized extraction and liquidchromatography-high resolution mass spectrometry, For. Science Int., 226 (2013) 88-93[5] Y.H. Lin, M.R. Lee, R.J. Lee, W.K. Ko, S.M. Wu. Hair analysis for methamphetamine,ketamine, morphine and codeine by cation-selective exhaustive inject
2015
Chiral separation, ketamine, norketamine, hair analysis
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/936644
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