UHPLC-MS/MS Determination of GeraniolGlycosides in Tea Shoots

A UHPLC-MS/MSmethod was developed to determine the contents of geraniolglucoside and geraniol primrose glucoside in tea shoots from various teacultivars. Pre-treatment and test conditions for the determination were optimizedto include the use of a C18 column (2.0μm, 2.1mm×100mm) and gradient elutionwith 0.1% (V/V) formic acid aqueous solution as mobile phase A and acetonitrileas mobile phase B under a flow rate of 0.3mL/min at a column temperature of 40℃.The ESI negative ionmode applied for the mass spectrometry yielded distinct peaks on the twocompounds with high resolution and sensitivity. Linearities of the workingcurves on both glycosides was obtained with r²≥0.9958 atthe detection limits of 44.7μg/kg and 22.3μg/kg and the quantitative limits of 149.0μg/kg and 74.3μg/kg. The average recoveries on the two glycosides were97.1% and 98.1%, and the average precisions 8.13% and 5.07%. Both glucosides were detected in partsof the new shoots of 6 tea varieties with decreasing contents in the maturingshoots. Within a same tea variety, the content of geraniol primrose glucosidewas higher than that of geraniol glucoside. The high glycosides content in teashoots are desirable for the making of oolong or aromatic black teas but notsuitable for green tea.