Flow Injection Spectrophotometric System for Determination of Flavonoids in Tea Using Modified Dowd Assay

摘要

ABSTRACT A simple, fast and reliable FI-system for the determination of flavonoids in tea was investigated. The proposed method was based on the reaction of sodium nitrite and aluminum chloride in alkaline solution, with spectrophotometric detection at 500 nm. The experimental parameters were optimized. Linear calibration graph was obtained in the range of 0.5-50.0 mg L-1 (as catechin). The relative standard deviations (n=20) were in the range 1.41-2.19%, with detection limit (S/N=3) was 0.03 m.