Screening of Amphetamines in Human Urine by Solid-Phase Extraction Coupled with UHPLC-QOrbitrap Mass Spectrometry

Abstract

We developed and validated a simple, sensitive, and reproducible analytical method using ultra high-pressure liquid chromatography (UHPLC)-QOrbitrap mass spectrometry to screen human urine samples for amphetamines. Amphetamines are classified under the group of abused drugs and are frequently used by jockeys. A rapid analysis method is necessary to ascertain the presence of minimal amounts of prohibited amphetamines in the urine samples of jockeys on a race day. For the method described herein, UHPLC conditions were set with a Luna Omega？？ C18 column using a gradient mobile phase. Six amphetamines were separated by gradient elution and detected by QOrbitrap MS in the positive ion mode. Validation parameters, including selectivity and limit of detection, were evaluated for the purpose of screening for amphetamines in human urine. Human urine samples were prepared for analysis using enzymatic hydrolysis and solidphase extraction. The limit of detection for screening the six amphetamines was between 0.1-10 ng/mL. We obtained recoveries between 31% and 76%, which is suitable for screening the amphetamines. This method combines the advantages of SPE and UHPLC-QOrbitrap MS, such as an effective extraction and simple analysis steps, and validated the amphetamine screening method for drug abuse control of jockies and improving public health.