Normal Flow and Stopped Flow Injection Spectrophotometric Determination of Quercetin Dihydrate Dietary Supplements

Abstract

Simple and sensitive normal flow injection(nFI) and stopped-FI spectrophotometric methods for the determination of quercetin dehydrate (QRC) in pure form were proposed, The methods were based on diazotization and coupling reaction between QRC and diazotized metoclopramide in alkaline medium to form orange-water soluble dye. The dye is stable and has a maximum absorbance at 438nm. A calibration graph shows that a Beers law is obeyed over the concentration range of 1-60µg.ml -1 and 0.8-50µg.ml -1 for (QRC) with a detection limit is 0.4166 µg.ml