High-Precision On-line Total Phenolic Compounds Analysis Oxidized by Folin Ciocalteu: Application to Ziziphus Jujuba Extract

Abstract

This study deals with a new methodology for total phenolic compounds on-line oxidation utilizing continuous flowing carrier stream technique provided by a system including a micropump, an auto-sampling and a reacting coil. Visible spectrophotometric measurement at 765 nm wavelength was based on fast oxidised phenols by Folin ciocalteu resulting in spectrophotometrically detectable blue chromophores. The reaction was automated to perform rapidity (sampling frequency 11 samples h-1), simplicity, reagents consuming and specificity. It offered a good linearity in a range of 10 - 50 mg mL-1 with no memory effect. It showed excellent precision (RSD lower than 0,4 %) with detection going less than 0,03 ηg.mL-1. The effectiveness of the developed method was verified by its application for the assay of total phenolic compounds in Ziziphus Jujuba fruit extract. This new method can be used as a quality-control tool for routine quantitative analysis of phenolic compounds in the different matrix. It opens up a number of application areas in health and environmental sciences, as well as measurements of body fluids in physiological and metabolic research.