Screening and confirmatory analysis of beta-agonists, beta-antagonists and their metabolites in horse urine by capillary gas chromatography-mass spectrometry.

The research article describes a method for analyzing the presence of beta-agonists, beta-antagonists, and their metabolites in horse urine using capillary gas chromatography-mass spectrometry. By applying this technique, different drugs were detected in the urine of horses after therapeutic administration.

Overview of the Research

• The study presents an approach for identifying and confirming the presence of basic drugs, namely beta-agonists and beta-antagonists, in equine urine. These classes of drugs can potentially enhance performance in race horses and therefore their use is commonly regulated or banned in professional horse racing.
• The method involves initial enzymic hydrolysis, a process that breaks down complex molecules into simpler ones, which prepares the sample for further analysis.

Extraction and Analysis Process

• After enzymic hydrolysis, the basic drugs and metabolites are extracted using specific cartridges (Clean Screen DAU or Bond Elut Certify cartridges). These cartridges are tools used to isolate particular substances for further analysis.
• The isolated substances are then analyzed as their trimethylsilyl ether or 2-(dimethyl) silamorpholine derivatives using a method called capillary gas chromatography-mass spectrometry. This sophisticated analytical technique separates components in a sample so they can be individually identified and quantified.

Evaluation and Results

• The proposed method was found to be highly sensitive and selective for basic drugs, enhancing its potential use in detecting banned substances in thoroughbred racing horses.
• After administering therapeutic doses of propranolol, metoprolol, timolol, isoxsuprine, and clenbuterol to thoroughbred horses, the remnants of these drugs or their metabolites were detectable in urine for a varied timeframe ranging from 14 to 120 hours, depending on the specific drug.