Identificación y caracterización de los productos de degradación de las benzotiadiazinas en orina humana. Importancia para el control antidoping

Abstract

The thiazides diuretics (benzothiadiazines) are widely used in the therapeutic. Like other diuretics can be
used illegally in sport with the aim to avoid a positive result or to reduce the athlete’s body weight to reach better results
in lower weight category. The thiazides diuretics are substances with the structure of 1,2,4-benzothiadiazine-7-
sulphonamide-1,1-dioxide with chloro or trifluoromethyl substitutes at 6th position and different other substitutes at 3rd
position. These compounds are very unstable due to the fact that no metabolic hydrolysis process and the ratio of parentcompound
to hydrolysis product is mainly governed by storage conditions of the urine sample. A stability study of urine
spiked with different benzothiadiazines is presented. Different temperature and time to determinate the degradation
product were assayed. The samples were prepared following a liquid-liquid extraction with ethyl acetate under alkaline
conditions and the analysis was carried out by Gas Chromatography-Mass Spectrometry. Identification of 2,4-
disuphonamide-5’-chloroaniline and 2,4-disulphonamide-5’-trifluoromethylaniline allowed respond to the World
Antidoping Agency requirements and to emit Adverse Analytical Finding in urine samples where this kind of diuretics
are absent or they are at very low concentration due to degradation process.