Morphine and codeine in racing horse feed: is there reason for concern?
Abstract: Opiates such as morphine and codeine are substances often misused to improve the performance of racing horses during competitions and are therefore on the International Federation for Equestrian Sports' list of prohibited substances. However, a positive antidoping test may be due to the consumption of feed (mainly lucerne or oats) contaminated by opium poppy containing the alkaloids morphine and codeine. In order to determine whether a positive antidoping test is the result of an intentional abuse of opiates or consumption of feed contaminated by poppies, we optimised conditions for the extraction of morphine and codeine from dehydrated lucerne and developed and validated a gas chromatography-mass spectrometry (GC-MS) method for the simultaneous determination of both analytes. The most efficient extraction of morphine and codeine from dehydrated lucerne was achieved using a citrate buffer pH4 followed by solid phase extraction. The method showed satisfactory linearity (R>0.9980) in the tested concentration range (85-1600 ng/g), as well as good precision (RSD95 %), and sensitivity (limit of detection 22 and 25 ng/g for morphine and codeine, respectively). The proposed method was used for analysing a sample of dehydrated lucerne having measurable content of morphine (1510 ng/g) and codeine (327 ng/g) that can cause positive results of opiate blood or urine testing up to 4 hours after feeding the horse with less than 500 g of dehydrated lucerne. The use of this analytical method should enable the exclusion of horse feed as the cause of positive antidoping tests. Opijati poput morfina i kodeina često se zloupotrebljavaju kako bi se poboljšala izvedba trkaćih konja tijekom natjecanja te se stoga nalaze na listi nedopuštenih sredstava Međunarodne konjičke federacije. Međutim, pozitivan antidopinški test može biti posljedica konzumiranja hrane (uglavnom lucerne ili zobi) onečišćene opijumskim makom koji sadrži morfin i kodein. Da bi se utvrdilo je li pozitivan antidopinški test posljedica namjerne zlouporabe opijata ili konzumiranja hrane kontaminirane makom, optimizirani su uvjeti ekstrakcije morfina i kodeina iz dehidrirane lucerne te je razvijena i validirana plinskokromatografska metoda uz detekciju spektrometrijom masa za istovremeno određivanje sadržaja oba ispitivana analita u dehidriranoj lucerni. Najučinkovitija ekstrakcija oba analita iz dehidrirane lucerne postignuta je korištenjem citratnog pufera pH=4 uz dodatno pročišćavanje ekstrakcijom na čvrstom nosaču. Metoda je pokazala zadovoljavajuću linearnost (R>0,9980) u ispitivanom koncentracijskom rasponu (85–1600 ng/g), kao i dobru preciznost (RSD95 %) i osjetljivost (granica detekcije=22 ng/g za morfin i 25 ng/g za kodein). Predloženom metodom analiziran je uzorak dehidrirane lucerne koji je sadržavao 1510 ng/g morfina i 327 ng/g kodeina što može rezultirati pozitivnim nalazom opijata u krvi i mokraći do 4 sata nakon što je konj nahranjen s manje od 500 g dehidiriane lucerne. Razvojem i validacijom ove analitičke metode omogućeno je isključivanje hrane za konje kao uzrok pozitivnog antidopinškog testa.
© 2025 Irena Brčić Karačonji et al., published by Sciendo.
Publication Date: 2025-03-31 PubMed ID: 40222175PubMed Central: PMC11994231DOI: 10.2478/aiht-2025-76-3888Google Scholar: Lookup
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Summary
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The research aims to outline an analytical method that ensures the differentiation of performance enhancing drug misuse in horses from potential feed contamination with codeine and morphine. It develops a Gas Chromatography-Mass Spectrometry (GC-MS) method and addresses the problem of positive test results due to feed contamination with poppy substances from ingredients like lucerne or oats.
Objective of the Research
- The research seeks to address a challenge in the horse racing industry, where there is a possibility of unfair accusations of performance-enhancing drug misuse levied against horses due to possible contamination of their feed.
- Specifically, the contamination in question involves opiates such as morphine and codeine, which are naturally present in the opium poppy and can accidentally contaminate feed ingredients like lucerne or oats.
- The research’s goal is to develop a method to help determine whether a positive drug test is a result of deliberate drug misuse or unintentional feed contamination.
Method Developed
- The researchers focused on optimizing the conditions for extracting morphine and codeine from dehydrated lucerne and validating a Gas Chromatography-Mass Spectrometry (GC-MS) method for simultaneous detection of the two substances.
- The research found citrate buffer of pH 4 to be the most effective for extracting morphine and codeine from the dehydrated lucerne. This was followed by a solid-phase extraction for further refinement.
- The method showed high accuracy, precision, and sensitivity, and enabled the determination of the concentration range of the substances in question.
Results and Conclusion
- A sample of dehydrated lucerne analyzed with this method exhibited a significant amount of morphine and codeine, lending credence to the hypothesis that horse feed could lead to positive opiate tests.
- The breakthrough here is the confirmation that feed can contain detectable levels of opiates that can cause a horse to test positive for them up to four hours after feeding on less than 500 grams of the dehydrated lucerne.
- This scientific work provides an analytical method that can effectively remove feed contamination by poppy substances as a cause of positive anti-doping tests in the horse racing industry.
Cite This Article
APA
Karačonji IB, Jelača T, Jurič A, Vrdoljak AL.
(2025).
Morphine and codeine in racing horse feed: is there reason for concern?
Arh Hig Rada Toksikol, 76(1), 60-66.
https://doi.org/10.2478/aiht-2025-76-3888 Publication
Researcher Affiliations
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
- University of Rijeka, Faculty of Health Studies, Rijeka, Croatia.
- University of Rijeka , Department of Biotechnology , Rijeka , Croatia.
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
- Institute for Medical Research and Occupational Health, Zagreb, Croatia.
MeSH Terms
- Animals
- Horses
- Codeine / analysis
- Animal Feed / analysis
- Morphine / analysis
- Gas Chromatography-Mass Spectrometry
- Substance Abuse Detection / methods
- Substance Abuse Detection / veterinary
- Doping in Sports
Conflict of Interest Statement
. The authors declare no conflict of interest.
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