Work

Detection of 4‐CPA and Its Related Metabolites Based on LC‐QE‐HF‐MS Technology: A Study on the Impact of Doping Test on the Intake Pathways of Chlorphenesin Carbamate and Chlorphenesin

Year: 2025

Type: article

Abstract: ABSTRACT Objective This study focused on meclofenoxate and its metabolite 4‐CPA in the field of doping control and examined the urinary metabolism of chlorphenesin carbamate and chlorphenesin, two substances that may produce 4‐CPA. Methods A liquid chromatography‐Q Exactive‐HF‐Orbitrap‐mass spectrometry (LC‐QE‐HF‐MS)–based assay was developed and validated for the accurate detection of the metabolites of 4‐CPA, chlorphenesin carbamate, and chlorphenesin and verified by human subject investigations. Human subjects were studied for three different modes of ingestion (chlorphenesin carbamate administration, sunscreen application containing chlorphenesin, and sunscreen spray application), and urine samples were collected before and after the administration to study the excretion profile of metabolites such as 4‐CPA. Results The developed assay meets the routine testing requirements of the World Anti‐Doping Agency. Following oral administration of chlorphenesin carbamate, 4‐CPA levels in the urine ranged from 390 to 6929 ng·mL −1 , reaching their maximum concentrations in 12–24 h, with two volunteers having values over the reporting limit. The highest excretion happened 12–24 h after the treatment and continued until 168–264 h later. The C max of 4‐CPA was 1354–2063 and 340 ng·mL −1 after application of sunscreen and spray sunscreen spray, respectively. Maximum excretion of other relevant metabolites was also concentrated at 12–24 h post‐dose. Conclusion The results suggest that when measuring 4‐CPA, the target analyte of meclofenoxate, in sports drug testing, special consideration needs to be given to whether volunteers have ingested normal therapeutic drugs, such as chlorphenesin carbamate, to avoid misreporting of meclofenoxate results. This finding offers crucial decision support for doping control.

Source: Rapid Communications in Mass Spectrometry

DOI: 10.1002/rcm.10004

Authors: Wennuo Xu, Jiahui Cheng, Zhongquan Li, Bing Niu, Xiaojun Deng, Bing Liu

Institutions: Shanghai University, Shanghai University of Sport

Language: English

Topic: Doping in Sports

Subfield: Sociology and Political Science

Field: Social Sciences

Domain: Social Sciences

SDG: Good health and well-being

Open Access status: bronze

Funder: Ministry of Science and Technology of the People's Republic of China