Fast and sensitive analysis of dermorphin and HYP6-dermorphin in equine plasma using liquid chromatography tandem mass spectrometry.

This research focuses on the development of a quick and sensitive method to detect the presence of dermorphin and HYP(6)-dermorphin, two potent opioids used for doping racehorses, in equine plasma.

Background

• The substances in question, dermorphin and HYP(6)-dermorphin, are hepta-peptides and natural opioids. These were originally isolated from the skin of South American frogs.
• These substances are more potent than morphine but tend to produce less drug tolerance and addiction. This makes them popular for illicit use in doping racehorses to enhance their performance.
• Dermorphin has been recently classified as a Class I drug by the Racing Commissioners International (RCI), making it a banned substance for use in equine athletes.

Scope of the study

• To enforce the ban on these substances, researchers designed a quick and precise method to analyse the presence of dermorphin and HYP(6)-dermorphin in equine plasma. Identifying these substances can help control their illicit use in equine sports.
• The researchers used 2 ml of equine plasma in their test method. They used a mixed mode cation exchange solid-phase column to extract the substances.
• Once extraction took place, the substances were separated and identified using a method known as liquid chromatography triple quadrupole linear ion trap mass spectrometry. The procedure uses positive multiple-reaction-monitoring (MRM) mode and each analysis took approximately 3.5 minutes.

Findings and Conclusion

• Four MRM transitions were used to identify each compound. The method showed efficient extraction procedure, and the limits of detection (LOD) were found to be 2 pg/ml for dermorphin and 10 pg/ml for HYP(6)-dermorphin.
• This analysis method showed good selectivity and precision.
• The researchers also conducted stability studies, proving that both drugs were stable at low temperatures.
• This research is the first report of an analysis of dermorphin and HYP(6)-dermorphin in equine plasma. The method could be adopted as a regular screening or confirmation method for controlling the abuse of these substances in equine sports.