ABSTRACT
Determination of caffeine is necessary for clinical research. A new method for the determination of caffeine in human urine was established by direct analysis in real time mass spectrometry using multiple reaction monitoring. The m/z 195.1 to 138.1 amu transition was employed in positive ionization mode. The preparation and analysis conditions were systemically optimized. The calibration curve was linear from 0.5–50 µg/mL with a limit of detection limit of 0.2 µg/mL. Intra-day and inter-day accuracy and precision were within the acceptable limits of ±15% at all concentrations. Moreover, the matrix effects for the determination of caffeine were evaluated. In conclusion, a simple, rapid, and reliable method without complex sample preparation and chromatographic separation was developed and validated for the determination of caffeine in human urine.
Acknowledgments
The authors acknowledge Professor Qing He Zhang and Engineer Zong Yang for kindly providing support and assistance.