Determination of vitamin B12 in equine urine by liquid chromatography – inductively coupled plasma – mass spectrometry.

This study investigates the presence of cobalt (as part of Vitamin B12) in horse urine, using a specialized analysis method. The relevance is defined by strict regulations in horse racing that penalize trainers for using cobalt salts, a performance enhancer, suggesting that checking for total urinary cobalt levels may not be enough to ensure fair play.

Objective and relevance

• This study begins with the context of horse racing, where using performance-enhancing substances like cobalt salts is strictly regulated. Trainers face severe penalties for presenting horses with high urine cobalt levels. Current regulations ensure compliance by analyzing total urinary cobalt with a threshold of 100 μg/L.
• However, cobalt is also a component of the cobalamin molecule (or Vitamin B12), which isn’t considered a performance enhancer.
• This leads to the main objective of the research – to understand and demonstrate the fact that a horse can excrete a significant portion of a Vitamin B12 injection via urine without metabolic modification, confusing it with harmful cobalt salts.

Methodology and Findings

• To achieve this, the researchers employed a specific analysis method known as liquid chromatography – inductively coupled plasma – mass spectrometry (LC-ICP-MS) for urinary cobalt speciation, i.e., identifying and understanding the different forms of cobalt in horse urine.
• The results demonstrated that a significant proportion of a commercially available Vitamin B12 injection can be excreted in horse urine without being metabolically modified. Essentially, this could be misinterpreted as a horse having consumed the prohibited cobalt salts.

Conclusion and Implications

• The researchers in their conclusion, infer that the existing methods of identifying the presence of cobalt in horse urine (total cobalt measurements) might not be sufficient to ensure fair play.
• This is because it might not differentiate between the prohibited inorganic cobalt and the harmless Vitamin B12 (containing cobalt). Hence, when ‘presumptive positives’ – instances where the measurements suggest the presence of cobalt salts – are identified by urine total cobalt measurements, further analysis should be undertaken.
• The findings encourage a more detailed analysis for fair and accurate regulation in the racing industry, in order to prevent false positives, thereby protecting the integrity of the sport and the reputations of innocent trainers.