Unexpected GC-MS Findings Following Immunoassay and TLC Screening in a Female Patient with Polysubstance Use: A Laboratory Case Repor
Keywords:
Polysubstance abuse, GC-MS, TLC, toxicology, drug testingAbstract
Polysubstance abuse is increasingly common and presents significant analytical challenges for toxicological laboratories. Standard screening methods such as immunoassay methods (for example urine dipstick test and enzyme modified immunoassay technique (EMIT)) and thin-layer chromatography (TLC) provide rapid detection but have limited specificity, particularly when structurally related compounds or adulterants are present. We report the case of a female patient with suspected substance abuse whose toxicological analysis revealed unexpected findings. Initial dipstick screening indicated polysubstance use. TLC supported some of the findings, particularly for cannabis; however, bands corresponding to other common drugs of abuse, including methamphetamine and morphine, were not observed. Therefore, gas chromatography–mass spectrometry (GC-MS) was performed as the final confirmatory analysis, which confirmed the absence of methamphetamine and morphine and instead detected pseudoephedrine and codeine. In addition, GC-MS analysis identified tramadol, another opioid, together with diazepam- and oxazepam-related benzophenone derivatives. The findings emphasize the need for confirmatory GC-MS in toxicological practice, ensuring precise identification of drugs and adulterants that may be overlooked by screening methods alone.
References
[1] Bonfiglio NS, Portoghese I, Renati R, Mascia ML, Penna MP. Polysubstance Use Patterns among Outpatients Undergoing Substance Use Disorder Treatment: A Latent Class Analysis. International Journal of Environmental Research and Public Health. 2022; 19(24):16759. https://doi.org/10.3390/ijerph192416759.
[2] Ciura K, Dziomba S, Nowakowska J, Markuszewski MJ. Thin layer chromatography in drug discovery process. Journal of Chromatography A. 2017 20;1520:9-22. doi: 10.1016/j.chroma.2017.09.015.
[3] Tamama K. Advances in drugs of abuse testing. Clinica Chimica Acta. 2021;514:40-47. doi: 10.1016/j.cca.2020.12.010.
[4] Green J, Lindqvist Bagge AS, Laporte N, Andiné P, Wallinius M, Hildebrand Karlén M. A latent class analysis of mental disorders, substance use, and aggressive antisocial behavior among Swedish forensic psychiatric patients. Comprehensive Psychiatry. 2023;127:152428. doi: 10.1016/j.comppsych.2023.152428
[5] Pentel P. Toxicity of over-the-counter stimulants. JAMA. 1984;252(14):1898-903. PMID: 6471321.
[6] Mercadante S, Arcuri E, Santoni A. Opioid-Induced Tolerance and Hyperalgesia. CNS Drugs. 2019;33(10):943-955. doi: 10.1007/s40263-019-00660-0.
[7] Jürgens G, Bauer JØ. Haloperidol and promethazine in psychotic aggression. Ugeskr Laeger. 2017;179(16):V69167.
[8] Lynch K, Shapiro B, Coffa D, Novak S, Kral A Promethazine use among chronic pain patients Drug Alcohol Dependence. 2015;150:92–97. doi: 10.1016/j.drugalcdep.2015.02.023
[9] Dinis-Oliveira RJ. Metabolic profile of oxazepam and related benzodiazepines: clinical and forensic aspects. Drug Metabolism Reviews. 2017;49(4):451-463.
[10] Levy S, Siqueira LM, Committee on Substance Abuse, Ammerman SD, Gonzalez PK, Ryan SA, Siqueira LM, Smith VC. Testing for drugs of abuse in children and adolescents. Pediatrics. 2014;133(6):e1798-1807.
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Journal of Biomedical and Clinical Sciences (JBCS) eISSN: 2550-147X
This work is licensed under a Creative Commons Attribution 4.0 International License.
JBCS Publication Ethics
JBCS is committed to ensure the publication process follows specific academic ethics. Hence, Authors, Reviewers and Editors are required to conform to standards of ethical guidelines.
Authors
Authors should discuss objectively the significance of research work, technical detail and relevant references to enable others to replicate the experiments. JBCS do not accept fraudulent or inaccurate statements that may constitute towards unethical conduct.
Authors should ensure the originality of their works. In cases where the work and/or words of others have been used, appropriate acknowledgements should be made. JBCS do not accept plagiarism in all forms that constitute towards unethical publishing of an article.
This includes simultaneous submission of the same manuscript to more than one journal. Corresponding author is responsible for the full consensus of all co-authors in approving the final version of the paper and its submission for publication.
Reviewers
Reviewers of JBCS treat manuscripts received for review as confidential documents. Therefore, Reviewers must ensure the confidentiality and should not use privileged information and/or ideas obtained through peer review for personal advantage.
Reviews should be conducted based on academic merit and observations should be formulated clearly with supporting arguments. In cases where selected Reviewer feels unqualified to review a manuscript, Reviewer should notify the editor and excuse himself from the review process in TWO (2) weeks time from the review offer is made.
In any reasonable circumstances, Reviewers should not consider to evaluate manuscripts if they have conflicts of interest (i.e: competitive, collaborative and/or other connections with any of the authors, companies, or institutions affiliated to the papers).
Editors
Editors should evaluate manuscripts exclusively based on their academic merit. JBCS strictly do not allow editors to use unpublished information of authors without the written consent of the author. Editors are required to take appropriate responsive actions if ethical complaints have been presented concerning a submitted manuscript or published paper.
CONFLICT OF INTEREST
Journal of Biomedical and Clinical Sciences requires authors to declare all competing interests in relation to their work. All submitted manuscripts must include a ‘competing interests section at the end of the manuscript listing all competing interests (financial and non-financial). Where authors have no competing interests, the statement should read ,The authors have declared that no competing interests exist. Editors may ask for further information relating to competing interests.
Editors and reviewers are also required to declare any competing interests and will be excluded from the peer review process if a competing interest exists. Competing interests may be financial or non-financial. A competing interest exists when the authors interpretation of data or presentation of information may be influenced by their personal or financial relationship with other people or organizations. Authors should disclose any financial competing interests but also any non-financial competing interests that may cause them embarrassment if they were to become public after the publication of the article.
HUMAN AND ANIMAL RIGHTS
All research must have been carried out within an appropriate ethical framework. If there is suspicion that work has not taken place within an appropriate ethical framework, Editors will follow the Misconduct policy and may reject the manuscript, and/or contact the author(s) institution or ethics committee. On rare occasions, if the Editor has serious concerns about the ethics of a study, the manuscript may be rejected on ethical grounds, even if approval from an ethics committee has been obtained.
Research involving human subjects, human material, or human data, must have been performed in accordance with the Declaration of Helsinki and must have been approved by an appropriate ethics committee. A statement detailing this, including the name of the ethics committee and the reference number where appropriate, must appear in all manuscripts reporting such research. Further information and documentation to support this should be made available to Editors on request.
Experimental research on vertebrates or any regulated invertebrates must comply with institutional, national, or international guidelines, and where available should have been approved by an appropriate ethics committee. The Basel Declaration outlines fundamental principles to adhere to when conducting research in animals and the International Council for Laboratory Animal Science (ICLAS) has also published ethical guidelines.
A statement detailing compliance with relevant guidelines (e.g. the revised Animals (Scientific Procedures) Act 1986 in the UK and Directive 2010/63/EU in Europe) and/or ethical approval (including the name of the ethics committee and the reference number where appropriate) must be included in the manuscript. The Editor will take account of animal welfare issues and reserves the right to reject a manuscript, especially if the research involves protocols that are inconsistent with commonly accepted norms of animal research. In rare cases, Editors may contact the ethics committee for further information.
INFORMED CONSENT
For all research involving human subjects, informed consent to participate in the study should be obtained from participants (or their parent or guardian in the case of children under 16) and a statement to this effect should appear in the manuscript, this includes to all manuscripts that include details, images, or videos relating to individual participants.
DATA SHARING POLICY
JBCS strongly encourages that all datasets on which the conclusions of the paper rely should be available to readers. We encourage authors to ensure that their datasets are either deposited in publicly available repositories (where available and appropriate) or presented in the main manuscript or additional supporting files, in machine-readable format (such as spreadsheets rather than PDFs) whenever possible
Authors who do not wish to share their data must state that data will not be shared, and give the reason.
COPYRIGHT NOTICE
The JBCS retains the copyright of published manuscripts under the terms of the Copyright Transfer Agreement. However, the journal permits unrestricted use, distribution, and reproduction in any medium, provided permission to reuse, distribute and reproduce is obtained from the Journal's Editor and the original work is properly cited.
While the advice and information in this journal are believed to be true and accurate on the date of its going to press, neither the authors, the editors, nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.
Copyright (c) 2023 Journal of Biomedical and Clinical Sciences (JBCS)
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
