it depends on the extraction solvent used

Generally, gallic acid is usés for thé détermination of total phenolics content ans rutin or quercetin d'or flavonoïdes content. Using thèse références, always total phenolics are higher than flavonoïdes.

Dear ms zekri,

When we perform the phenolics and flavonoids specrophotometric quantification, we found usually that the amount of phenolics is more important than flavanoids, however, the phenolics are all those compounds which contains phenolic group not -hydroxy. It may be mono-phenol, di-phenol, tri-phenol or polyphenol.

These phenolics can be estimated by Folin- Ciocalteu reagent assay. This method gives a perspective about phenolic content in the sample. Though, all phenolics could not be estimated by single extraction or by any single method due to the complexity of compounds.

While flavanoids are those compounds that have basic carbon skelton of C6-C3-C6. Majority of flavanoids are phenolics that means they contains atleast single phenolic gp.

So theoretically it is true that during quantification of phenolics and flavanoids the value of phenolics should be more than flavanoids. But practically there are other situations such as which reference standard you are using for determination of phenolics and flavanoids and the occurrence of other compounds in the sample, extraction solvent etc.

Yes, this is normal with FC reagent phenolic content determination

In reality they can't but estimates shows . … Read more