To establish a method for determination of 21 kinds of pyrrolizidine alkaloids in tea by QuEChERS pretreatment combined with ultra performance liquid chromatography-tandem mass spectrometry.

Tea samples were first hydrated with water, extracted by 0.1% formic acid acetonitrile, purified by QuEChERS, and then filtered by microporous filter membrane, the filtrate was directly for analysis. The samples were measured in electrospray positive ion source and multi-reaction monitoring mode.

Within each specified concentration range, 21 kinds of pyrrolizidine alkaloids showed excellent linearity, with the correlation coefficient (r²) exceeding 0.998. The limits of detection were 0.03–3.00 μg/kg, limits of quantitation were 0.10–10.00 µg/kg. while the average recovery rates varied from 81.3% to 116.3% and the relative standard deviations were between 0.5% and 10.6%.

The method is simple and rapid, and can meet the detection requirements of pyrrolizidine alkaloids in tea. Meanwhile, when applied to the detection of commercially available tea samples, it is found that some samples contained lycopsamine, lycopsamine N-oxide and intermedine.