Magnetic graphene dispersive solid phase extraction-ultra performance liquid chromatography tandem mass spectrometry for determination of β-agonists in urine.

In this study, a magnetic graphene-based dispersive solid phase extraction method was first developed for extraction of β-agonists in urine. During the experiments, the absorbent amount, sample pH, extraction time, elution solution and elution time were optimized respectively. The optimized extraction method was finished within 10min, and showed high enrichment factors for 9 β-agonists (20-26 folds). Furthermore, this absorbent could be reused for at least 60 times. Then this extraction method was combined with ultra performance liquid chromatography triple quadrupole tandem mass spectrometry to determine the 9 drugs in urine. The limits of detection for the 9 drugs were in a range of 0.015-0.023ngmL, and the recoveries from the standards fortified blank urine were in a range of 60.2%-109.4%. Therefore, this method could be used as a simple, rapid, sensitive and accurate tool to determine trace level of β-agonists in urine.