( G. Vjial M. Lamor V. Pop an...)Screening of Corticosteroids in Urine by Negative Atmospheric Pressure Chemical Ionization LC/MS/MS

G. Vjial, M. Lamor, V. Pop and G. Bican, Doping Control Laboratory, Bucharest, Romania

Introduction

Corticosteroids are a class of components often abused and misused in sport. They are very potent drugs in the treatment of inflammations and asthma [1]. Corticosteroids can have an effect on the nervous system and can improve an athletes ability to concentrate and perform in endurance and power events [2,3]. Moreover, corticosteroids can alleviate pain in general. To prevent their misuse related to euphoria and pain suppression, the anti-doping governing bodies are restricting the use of corticosteroids. Systemic use of corticosteroids is forbidden in all circumstances. However, when medically necessary, local and intra-articular injections or dermatological preparations are allowed under the approval of a therapeutic use exemption [4].

The samples collected for doping control are mainly urine samples because large sample volumes can be collected in a non-invasive way. Therefore, the abuse of corticosteroids is analyzed using urine samples.

A simple and sensitive LC/MS/MS method for the screening of 17 corticosteroids is described below. The method is able to detect corticosteroids from the doping control urine samples at 20 ng/mL below the WADA minimum required performance level (MRPL), which is 30 ng/mL.

Instrumentation

Varian ProStar 430 AutoSampler

Varian ProStar 210 Solvent Delivery Modules

Varian 1200L LC/MS equipped with Atmospheric Pressure Chemical Ionization (APCI) source

Harvard Syringe Pump model 11 Materials and Reagents

Standards of corticosteroids, from Sigma-Aldrich, USA Methanol, gradient grade for liquid chromatography, from Merck, Germany

Water supplied by a Simplicity 185 ultrapure water system, from Millipore, Great Britain<
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