Journal Article

A Gas Chromatography-Mass Spectrometry Method for the Quantitation of CIobenzorex*

John T. Cody and Sandra Valtier

in Journal of Analytical Toxicology

Volume 23, issue 7, pages 603-608
Published in print November 1999 | ISSN: 0146-4760
Published online November 1999 | e-ISSN: 1945-2403 | DOI:
A Gas Chromatography-Mass Spectrometry Method for the Quantitation of CIobenzorex*

More Like This

Show all results sharing these subjects:

  • Medical Toxicology
  • Toxicology (Non-medical)


Show Summary Details


Drugs metabolized to amphetamine or methamphetamine are potentially significant concerns in the interpretation of amphetamine-positive urine drug-testing results. One of these compounds, clobenzorex, is an anorectic drug that is available in many countries. Clobenzorex (2-chlorobenzylamphetamine) is metabolized to amphetamine by the body and excreted in the urine. Following administration, the parent compound was detectable for a shorter time than the metabolite amphetamine, which could be detected for days. Because of the potential complication posed to the interpretation of amphetamine-positive drug tests following administration of this drug, the viability of a current amphetamine procedure using liquid-liquid extraction and conversion to the heptafluorobutyryl derivative followed by gas chromatography-mass spectrometry (GC-MS) analysis was evaluated for identification and quantitation of clobenzorex. Qualitative identification of the drug was relatively straightforward. Quantitative analysis proved to be a far more challenging process. Several compounds were evaluated for use as the internal standard in this method, including methamphetamine-d11, fenfluramine, benzphetamine, and diphenylamine. Results using these compounds proved to be less than satisfactory because of poor reproducibility of the quantitative values. Because of its similar chromatographic properties to the parent drug, the compound 3- chlorobenzylamphetamine (3-Cl-clobenzorex) was evaluated in this study as the internal standard for the quantitation of clobenzorex. Precision studies showed 3-Cl-clobenzorex to produce accurate and reliable quantitative results (within-run relative standard deviations [RSDs] < 6.1%, between-run RSDs < 6.0%). The limits of detection and quantitation for this assay were determined to be 1 ng/mL for clobenzorex.

Journal Article.  0 words. 

Subjects: Medical Toxicology ; Toxicology (Non-medical)

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.