TY - JOUR KW - Adult KW - Analgesics, Opioid/metabolism/therapeutic use/urine KW - Biotransformation KW - Chromatography, Ion Exchange KW - Drug Monitoring/methods/standards KW - Female KW - Gas Chromatography-Mass Spectrometry KW - Heroin Dependence/diagnosis/metabolism/rehabilitation/urine KW - Humans KW - Limit of Detection KW - Linear Models KW - Male KW - Methadone/metabolism/therapeutic use/urine KW - Middle Aged KW - Nails/metabolism KW - Opiate Substitution Treatment/methods KW - Predictive Value of Tests KW - Reproducibility of Results KW - Solid Phase Extraction KW - Substance Abuse Detection/methods/standards AU - T. P. Magalhaes AU - S. Cravo AU - D. D. D. Silva AU - R. J. Dinis-Oliveira AU - C. Afonso AU - Lourdes Bastos AU - H. Carmo A1 - AB - The quantification of drugs of abuse in keratinized matrices is becoming of special relevance for monitoring consumption and for post-mortem investigations. We aimed to implement an analytical method for the simultaneous detection of morphine (MORF), 6-monoacetylmorphine (6-MAM), methadone (MET), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrrolidine (EMDP) in nails. After decontamination, the nail samples (30 mg) were submitted to an alkaline digestion followed by a two-step liquid-liquid and SPE extraction using mixed-mode cation exchange cartridges. The analytes were eluted with 5% NH4OH/methanol. After derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide, the analytes were quantified by gas chromatography-mass spectrometry. The method was optimized and fully validated only for MET, EDDP and EMDP, since for MOR and 6-MAM it was not possible to obtain adequate recovery rates after extraction, although detection of MOR was still possible. The method was selective, accurate and precise. Regression analysis demonstrated linearity over a concentration range of 20.8-333.3 ng/mg for MET and 10.4-166.7 ng/mg for EDDP and EMDP. Limits of detection and quantification values ranged from 3.3 to 6.0 ng/mg and 10.4 to 20.8 ng/mg, respectively, and recovery rates ranged from 82% to 98%. The applicability of the method was demonstrated by analyzing nail and urine samples obtained from heroin consumers under substitution therapy with MET. BT - Journal of analytical toxicology C5 - Opioids & Substance Use CP - 3 CY - England DO - 10.1093/jat/bkx099 IS - 3 JF - Journal of analytical toxicology N2 - The quantification of drugs of abuse in keratinized matrices is becoming of special relevance for monitoring consumption and for post-mortem investigations. We aimed to implement an analytical method for the simultaneous detection of morphine (MORF), 6-monoacetylmorphine (6-MAM), methadone (MET), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrrolidine (EMDP) in nails. After decontamination, the nail samples (30 mg) were submitted to an alkaline digestion followed by a two-step liquid-liquid and SPE extraction using mixed-mode cation exchange cartridges. The analytes were eluted with 5% NH4OH/methanol. After derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide, the analytes were quantified by gas chromatography-mass spectrometry. The method was optimized and fully validated only for MET, EDDP and EMDP, since for MOR and 6-MAM it was not possible to obtain adequate recovery rates after extraction, although detection of MOR was still possible. The method was selective, accurate and precise. Regression analysis demonstrated linearity over a concentration range of 20.8-333.3 ng/mg for MET and 10.4-166.7 ng/mg for EDDP and EMDP. Limits of detection and quantification values ranged from 3.3 to 6.0 ng/mg and 10.4 to 20.8 ng/mg, respectively, and recovery rates ranged from 82% to 98%. The applicability of the method was demonstrated by analyzing nail and urine samples obtained from heroin consumers under substitution therapy with MET. PP - England PY - 2018 SN - 1945-2403; 0146-4760 SP - 192 EP - 206 EP - T1 - Quantification of Methadone and Main Metabolites in Nails T2 - Journal of analytical toxicology TI - Quantification of Methadone and Main Metabolites in Nails U1 - Opioids & Substance Use U2 - 29244080 U3 - 10.1093/jat/bkx099 VL - 42 VO - 1945-2403; 0146-4760 Y1 - 2018 ER -