Analysis of Procyanidins in Rock Tea Shuikuling Rougui by Liquid Chromatography-Tandem Mass Spectrometry

The procyanidins in the rock tea shuikuling rougui were identified and determined by liquid chromatography-tandem mass spectrometry(HPLC-ESI-MS/MS) technique with the multiple-reaction monitoring mode. The catechins, epicatechin, epicatechin gallate and procyanidins B₂ were separated and identified successfully by Waters SunFire-C₁₈ column（150 mm×2.1 mm×5 μm），with 0.1％formic acid solution and acetonitrile as the mobile phase in gradient elution, flow velocity was 0.25 mL/min, column temperature was 25 ℃，and sample volume was 3 μL. The linear regression equation and correlation coefficient of the catechins, epicatechin, epicatechin gallate and procyanidins B₂ are y₁=642.48x-63.693, r=0.999 5; y₂=550.45x+10.386, r=0.999 6; y₃=2 261.5x-1 320.0, r=0.999 5 and y₄=4 598.5x-4 079.0, r=0.999 5， respectively. The linear ranges are 5.00—150.00 mg/L，the recoveries are 93.9％—108.0％, the coefficients of variation are less than 7.53% and the limit of detection are 0.005 5—0.013 2 μg/g。