Detection of testosterone propionate administration in horse hair samples.

The research presents a new method to semi-quantitatively detect testosterone presence in horse hair samples. The technique has high sensitivity and specificity, with an ability to detect less than 1 pg mg(-1) and a recovery rate near 90%.

Methodology

• The process begins with a washing step using a sodium dodecylsulfate aqueous solution. This helps in cleaning the hair samples.
• The mane and tail hair samples, weighing approximately 100mg each, are then dissolved in 1 mL of sodium hydroxide. The samples are treated for 15 minutes at a temperature of 95 degrees Celsius. This step uses an internal standard d3-boldenone.
• Following the dissolution, the sample undergoes diethyl ether extraction and a solid phase extraction on Isolute C18 (EC) cartridges, eluted with methanol. This step is aimed at the extraction of any remaining impurities from the sample.
• The residuary sample is then derivatized with the addition of 100 microL of acetonitrile and 30 microL of PFPA. This is incubated for 15 min at 60 degrees C. The primary goal here is to separate the ions of interest from the rest.
• After evaporation, 30 microL of hexane is added and a small volume (2.5 microL) is injected into the column of a Trace GC chromatograph. The column has specific dimensions and the chromatograph helps in the separation of components of the sample.
• The detection of testosterone takes place through MS(2) full scan mode on the Polaris Q instrument, improving the sensitivity of the method.

Results

• The methodology was found to be highly sensitive, capable of detecting testosterone levels below 1 pg mg(-1).
• It had a high recovery rate, close to 90%.
• The technique was tested on real-world samples – mane and tail hair from a gelding horse that had been given a single dose of testosterone propionate. The presence of testosterone was detected in the range of 1-6 pg mg(-1) in hair collected over the course of five months post-administration.

Conclusion

• This proposed method provides an efficient way to detect testosterone in horse hair, potentially serving as a detection tool for illicit use of performance-enhancing drugs in equine sports.