Determination of 4 psychoactive substances in tea using ultra high performance liquid chromatography combined with the quadrupole time-of-flight mass spectrometry

Abstract

In this study, a method for the qualification and quantification of 4 psychoactive substances in tea using ultra high performance liquid chromatography coupled with the quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) has been developed. Tea samples were extracted by a 50% (v/v) methanol–water solution, and then separated by an ACQUITY UPLC BEH Shield RP18 column using a binary solvent system by gradient elution. The analytes were determined by Q-TOF/MS in TOFMS and information-dependent acquisition (IDA)-MS/MS mode. The results showed that the mass accuracy error of the 4 psychoactive substances were lower than 5.0 × 10⁻⁶, and a good linear relationship was observed in the range of 0.5–500 μg L⁻¹ and correlation coefficient was higher than 0.9990. The LOD was in the range of 0.005–0.020 mg kg⁻¹ and the LOQ was in the range of 0.010–0.040 mg kg⁻¹. The recovery of the method was in range of 80.14–93.25% with spike levels of 0.010–0.400 mg kg⁻¹, and relative standard deviations were lower than 10%. The method was simple, specific and reliable. It has been successfully used for the detection of 4 psychoactive substances in tea samples.