DEVELOPMENT AND VALIDATION OF A LIQUID CHROMATOGRAPHY – TANDEM MASS SPECTROMETRY METHOD FOR CANNABIS DETECTION IN HAIR OF CHRONIC CANNABIS USERS UNDER SURVEILLANCE

Authors

  • Muhammad Aamir
  • Ayesha Hafeez
  • Aamir Ijaz
  • Saleem Ahmed Khan
  • Nayyar Chaudhry
  • Nisar Ahmed

Abstract

Objective: To develop and validate a method on liquid chromatography-mass spectrometry for simultaneous detection of two cannabinoid metabolites in hair and to subsequently apply this method for surveillance of chronic cannabis users.

Study design: Cross sectional (validation) study.

Place & duration of study: Departments of Forensic Medical Sciences Laboratory, Forensic Toxicology Section, Armed Forces Institute of Pathology, Rawalpindi Pakistan.

Materials and Methods: Hair samples from about 60 chronic cannabis addicts were collected. After washing, decontamination and alkaline hydrolysis, the samples were extracted with n-hexane: ethyl acetate, centrifuged and reconstituted with methanol. Separation of compounds was achieved with Agilent Poroshell 120 EC-C18 column (2.1 x7.5mm.7 micron). For detection and quantification, a 6460 Tripple quadrapole LCMS having an ESI source with jet steam technology alongwith software Mass hunter was used.

Results: Intra- and inter-assay bias was below 8% and relative standard deviation below 10% for both metabolites. The limit of quantification for both THC and THC-COOH were validated at 100pg/mg. The method was validated in terms of linearity, carry over, selectivity (no endogenous or exogenous interferences); precision and accuracy; limits of detection and quantification and matrix effects (ion suppression and enhancement). It was then applied to testing of real hair samples from 55 chronic cannabis users.

Conclusion: The presented method allows simultaneous quantitation of THC and THC- COOH in hair of chronic cannabis users under surveillance, utilizing LCMS. Analysis for drugs of abuse in hair however remains a formidable analytical challenge and laboratories need to develop methodologies which efficiently release the drug from its solid matrix and are free from interferences to achieve the desired sensitivity.

Keywords: Liquid chromatography-mass spectrometry, Cannabinoid, Validation.

Author Biographies

Muhammad Aamir

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan

Ayesha Hafeez

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan  

Aamir Ijaz

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan

Saleem Ahmed Khan

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan

Nayyar Chaudhry

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan

Nisar Ahmed

Armed Forces Institute of Pathology(National University of Medical Sciences), Rawalpindi, Pakistan

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Published

25-10-2016

How to Cite

1.
Aamir M, Hafeez A, Ijaz A, Khan SA, Chaudhry N, Ahmed N. DEVELOPMENT AND VALIDATION OF A LIQUID CHROMATOGRAPHY – TANDEM MASS SPECTROMETRY METHOD FOR CANNABIS DETECTION IN HAIR OF CHRONIC CANNABIS USERS UNDER SURVEILLANCE. Pak J Pathol [Internet]. 2016 Oct. 25 [cited 2024 Mar. 29];27(2). Available from: http://pakjpath.com/index.php/Pak-J-Pathol/article/view/350

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