Morphine and codeine in racing horse feed: is there reason for concern?

Area of Science:

• Analytical Chemistry
• Forensic Toxicology
• Equine Sports Science

Background:

• Opiates like morphine and codeine are prohibited in equestrian sports due to performance-enhancing misuse.
• Accidental positive anti-doping tests can occur from consuming feed (lucerne, oats) contaminated with opium poppy alkaloids.
• Distinguishing intentional opiate abuse from feed contamination is crucial for fair competition.

Purpose of the Study:

• To optimize opiate extraction from dehydrated lucerne.
• To develop and validate a gas chromatography-mass spectrometry (GC-MS) method for simultaneous morphine and codeine determination.
• To differentiate between intentional opiate use and feed contamination in equine anti-doping.

Main Methods:

• Optimized extraction using citrate buffer (pH 4) followed by solid-phase extraction.
• Validated a GC-MS method for simultaneous determination of morphine and codeine.
• Method validation included linearity (R²>0.9980), precision (RSD<4%), accuracy (>95%), and sensitivity (LOD 22-25 ng/g).

Main Results:

• The optimized extraction and GC-MS method demonstrated high accuracy and sensitivity.
• Analyzed lucerne sample contained 1510 ng/g morphine and 327 ng/g codeine.
• Less than 500g of contaminated lucerne can lead to positive opiate tests up to 4 hours post-consumption.

Conclusions:

• The developed GC-MS method reliably quantifies morphine and codeine in equine feed.
• This analytical approach can exclude contaminated feed as the source of positive opiate tests.
• Supports fair play in equestrian sports by providing a tool to investigate doping allegations.