SOFT 2004 Meeting Abstracts - Society of Forensic Toxicologists

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A37
HIGH THROUGHPUT SCREENING OF CORTICOSTEROIDS AND BASIC DRUGS IN HORSE
URINE BY LC-MS-MS
Gary N. W. Leung, Evonne W. Chung, Emmie N. M. Ho, W. H. Kwok, David K. K. Leung, Francis P. W.
Tang, Terence S.M. Wan*, and Nola H. Yu
Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China;
terence.sm. wan@hkjc.org.hk
Introduction: Gas chromatography - mass spectrometry (GC-MS) has long been accepted as a powerful
technique for the screening and confirmation of the presence of prohibited substances in biological samples
from human and animal athletes. Over the past decade, liquid chromatography - mass spectrometry (LC­
MS) has evolved into a mature technique and is gaining wide acceptance in many doping control
laboratories. LC-MS or LC-MS' is particularly suited for the analyses of polar, non-volatile and heatlabile
drugs that cannot be adequately handled by GC-MS. In addition, tedious derivatization steps can
often be omitted. This paper describes two high throughput LC-MS-MS methods for the screening of two
important classes of drugs in equine sports, namely the corticosteroids and the basic drugs, at low ppb
levels in horse urine. The method utilized a high efficiency reversed phase LC column (3 cm L x 2.1 mm
ID with 2.5 Jlm particles) to provide fast turnaround times as well as achieving significant reduction in the
consumption of expensive HPLC solvents. The performance of these two methods on real samples was
demonstrated by analysing drug administration and positive postrace urine samples.
Method: Corticosteroids and basic drugs were extracted from enzyme-treated urine by solid-phase
extraction using a Bond Elut CertifY® cartridge and analysed by LC-MS-MS in multiple reaction
monitoring (MRM) mode using a Thermo Finnigan triple quadrupole TSQ Quantum mass spectrometer.
Separation of the corticosteroids and basic drugs was achieved using a short reversed-phase CI8 column (3
cm Lx 2.1 mm ID with 2.5 Jlm particles) on two different LC gradient solvent systems.
Results: Using the methods developed in this study, the detection of 23 corticosteroids and 42 basic drugs
could be achieved within a 2.5-min and a 3.5-min LC-MS-MS run respectively. The overall turnaround
time for the corticosteroid screen was 5 minutes and that for the basic drug screen was 8 minutes, inclusive
of post-run and equilibration times. The results on the analysis of drug administration and positive
postrace urine samples also demonstrated that both methods were effective in detecting corticosteroids and
basic drugs in horse urine at low ppb levels.
Conclusion: Two high throughput LC-MS-MS methods with the use of a high efficiency LC column have
been developed for the screening of corticosteroids and basic drugs at low ng/mL levels in equine urine.
Validation data will also be presented. These methods can be used to control the abuse of these two classes
of drugs in racehorses.
Keywords: Corticosteroids, Basic drugs, High throughput LC-MS-MS
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