Detection of diuretics in horse urine by GC/MS.

The research presents a methodology to detect three commonly used diuretics in horse urine by Gas Chromatography/Mass Spectrometry, providing a tool to aid in the control of horse doping.

Research Objectives

• The main objective of the study was to develop a sensitive and efficient technique to detect the use of different types of diuretics in horses. The use of diuretics is prohibited in horses due to its potential use in doping.
• The researchers aimed to detect three commonly used acidic diuretics – bumetanide, ethacrynic acid, and furosemide in horse urine.

Methodology

• The researchers employed a liquid-liquid extraction on Extrelut 3, under weak acidic and basic conditions utilizing ethyl acetate as an organic solvent.
• For analysis, the diuretics were methylated on-column in the presence of MSTFA/TMAH. This steered clear of the typically employed highly toxic derivative agent, methyl iodide.
• To identify the diuretics, a mass selective detector operating in the SIM (selected ion monitoring) mode was used. The researchers explain that confirmation analysis could be obtained with a full scan run.
• The recoveries for the different drugs varied between 31 to 48% when using 3 mL of urine at the 100-ng/mL level. The calibration curves of the drug standards shown linearity from 2.5 to 20 ng injected.

Findings

• The method could detect as low as 40ng/mL level of the three diuretics in horse urine.
• It was found that the method permits rapid and sensitive detection of diuretics in horse urine, hence it is recommended for doping control.

Significance

• In light of the findings, this method will aid in controlling horse doping by efficiently detecting diuretics in horse urine.
• The technique provides a safer alternative to traditional methods, as it avoids the use of the highly toxic derivative agent, methyl iodide.