DETERMINATION OF TEA POLYPHENOLS IN GREEN TEA USING FLOW INJECTION-CHEMILUMINESCENCE INHIBITION

AIMTo establish a flow injection chemiluminescence (CL) inhibition method for determination of tea polyphenols in green tea. METHODSThe flow line of the sample, H₂O₂ and KIO₄ was inserted into luminol carrier solution. The mixed solution was led into the chemiluminescence cell for chemiluminescence reaction to occur and the CL intensity was recorded. RESULTSTea polyphenols was shown to inhibit the CL reaction of luminol-H₂O₂-KIO₄ system in alkaline solution and the CL emission was inversely correlated with the tea polyphenols concentration. The linear range was 0.4～24.0 μg·mL^-1 with a detection limit of 0.03 μg·mL^-1 and a relative standard deviation of 1.3% (at tea polyphenols concentration 4.0 μg·mL^-1, N=11). The sampling frequency was 240·h^-1. CONCLUSION The method is simple, rapid and can be used for determination of tea polyphenols in green tea.