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Simultaneous quantification of morphine and cocaine in hair samples from drug addicts by GC-EI/MS

Gouveia, Carla Alexandra, Oliveira, Ana, Pinho, Sandra, Vasconcelos, Carlos, Carvalho, Félix, Moreira, Roxana Falcão, Dinis-Oliveira, Ricardo Jorge (2012) Simultaneous quantification of morphine and cocaine in hair samples from drug addicts by GC-EI/MS. Biomedical Chromatography, 26 (8). pp. 1041-1047. ISSN 0269-3879. (doi:10.1002/bmc.2775) (Access to this publication is currently restricted. You may be able to access a copy if URLs are provided) (KAR id:98388)

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The development of analytical techniques that enable the use of hair as an alternative matrix for the analysis of drugs of abuse is useful for confirming the exposure in a larger time window (weeks to months, depending on the length of the hair shaft). In the present study a methodology aimed at the simultaneous quantification of cocaine and morphine in human hair was developed and validated. After decontamination, hair samples (20 mg) were incubated with a mixture of methanol/hydrochloric acid (2:1) at 65 °C overnight (~16 h) in order to extract the drugs of the matrix. Purification was performed by solid-phase extraction using mixed-mode extraction cartridges. After derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide, blank, standards and samples were analyzed by gas chromatography/electron impact–mass spectrometry (GC-EI/MS). The method proved to be selective, as there were no interferences of endogenous compounds with the same retention time as cocaine, morphine and ethylmorphine (internal standard). The regression analysis for both analytes showed linearity in the range 0.25–10.00 ng/mg with correlation coefficients ranging from 0.9989 to 0.9991. The coefficients of variation oscillated between 0.83 and 14.60%. The limits of detection were 0.01 and 0.02 ng/mg, and the limits of quantification were 0.03 and 0.06 ng/mg for cocaine and morphine, respectively. The proposed GC-EI/MS method provided an accurate and simple assay with adequate precision and recovery for the quantification of cocaine and morphine in hair samples. The proof of applicability was performed in hair samples obtained from drug addicts enrolled in a Regional Detoxification Treatment Center. The importance of hair samples is highlighted, since positives results were obtained when urine immunoassay analyses were negative.

Item Type: Article
DOI/Identification number: 10.1002/bmc.2775
Subjects: R Medicine
Divisions: Divisions > Division of Natural Sciences > Kent and Medway Medical School
Depositing User: Ana Oliveira
Date Deposited: 27 Nov 2022 16:09 UTC
Last Modified: 02 Dec 2022 09:38 UTC
Resource URI: (The current URI for this page, for reference purposes)

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Oliveira, Ana.

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