Simultaneous Analysis of Catechins in Several Fujian Oolong Tea and White Tea Products by UPLC-MS/MS

Objective:A rapid ultrahigh performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry(UPLC-MS/MS)method was established for the simultaneous determinationof eight catechin compounds including catechin(C),epicatechin(EC),gallocatechin(GC),epigallocatechin(EGC),epigallocatechin gallate(EGCG)in several Fujian tea products(oolong tea and white tea).Method:The compounds were separated on a waters T3 C₁₈ column with 0.1%(V/V)formic acid aqueous solution and methanol as mobile phase by gradient elution,then analyzed by positive electrospray ionization tandem mass spectrometry under multiple reaction monitoring(MRM)mode. Results:8 catechin compounds could be detected in 8 wmiutes,the limits of detection(LOD)were in the range of 0.2~1.1 μg/L and there was a good linearity over tested concentration ranges with the correlation coefficients(r)from 0.9966 to 0.9994.The content of epigallocatechin gallate(EGCG)was much higher than other catechin compounds in all the testing samples,which could up to 60% of the total catechins. The results showed that the content of total catechins was 43.59~45.21 mg/g in oolong tea,and from 50.52 to 70.71 mg/g in white tea. Conclusion:The method employed to detect 8 catechin compounds was sensitive,quick and accurate,and the study could provide scientific evidences for the utilization of Fujian tea products.