A hydrophobic deep eutectic solvent-based vortex-assisted liquid-liquid microextraction applied for doping control of aromatase inhibitors from equine urine.

This study discusses a method to detect Aromatase inhibitors (AIs) in horse urine samples for doping control.

Introduction to Aromatase inhibitors (AIs):

• Aromatase inhibitors can cause an indirect increase in testosterone levels in animals.
• This boost in testosterone can enhance the athletic performance of horses.
• Due to potential harm to horses and to maintain a level playing field in competitions, AIs are banned by the Federation Equestre Internationale (FEI).

Problem with Traditional Methods:

• There were certain disadvantages when using the older methods to analyze these drugs from biological samples (like horse urine). The exact problems aren’t specified here, but they might include longer processing times, higher costs, or less accurate results.

Introduction to the New Method:

• A new method, which is faster and more environmentally friendly, has been developed.
• This method uses hydrophobic deep eutectic solvent (DES)-based vortex-assisted liquid-liquid microextraction (DES-VALLME). In simpler terms, this is a technique where a special solvent (DES) is used to extract AIs from urine samples, and this extraction is aided by vortexing (stirring or spinning).
• After extraction, an advanced analytical technique called ultra-high performance liquid chromatography tandem triple-quadrupole mass spectrometry (UHPLC-MS/MS) is used to detect and quantify the AIs.

Specifics of the Method:

• The best solvent (DES) for this extraction was found to be a combination of menthol and 4-fluorophenol in a specific ratio (1:4).
• The method is efficient: Only 80 μL of the DES solvent and 1 mL of horse urine are needed, and the entire process takes just 2 minutes.
• The method is accurate and sensitive: It can detect AIs in a broad concentration range (from 0.02 to 4000 ng mL-1) with high reliability (r^2 ≥ 0.9983). Moreover, the lowest amounts it can detect (limits of detection) are between 0.01 and 4 ng mL-1.
• The accuracy of the method is commendable with recoveries between 94.9% and 113.4% and with very consistent results (both intra-day and inter-day variations are less than 9.1%).

Advantages of the New Method over Traditional Ones:

• It’s fast, simple, efficient.
• Environmentally friendly (low toxicity).
• Cost-effective.

Conclusion:

• This new method offers great potential for doping control in the equestrian world, ensuring that competitions remain fair and horses aren’t subjected to harmful substances.

In essence, the study introduces a new and efficient method to detect prohibited drugs in horse urine, ensuring the well-being of the horses and the integrity of the sport.