I am getting the total phenolics content and total flavonoids content of a sample. Should the TFC be always lower in value? I know that flavonoids are prt of phenolics but since the protocols and standards are different, the protocols somehow produced darker liquids for the TFC which of course gave higher absorbance reading.

The protocol I used:

TPC

The test sample (0.2 mL) was mixed with 0.6 mL of water and 0.2 mL of Folin-Ciocalteu’s phenol reagent (1 : 1). After 5 min, 1 mL of saturated sodium carbonate solution (8% w/v in water) was added to the mixture and the volume was made up to 3 mL with distilled water. The reaction was kept in the dark for 30 min and after centrifuging the absorbance of blue color from different samples was measured at 765 nm.

TFC

1 mL quercetin of each concentration or extract was added to the test tube containing 4 mL of distilled water. At the same time, 0.3 mL of 5% NaNO2 was added to the test tube and 0.3 mL of 10% AlCl3 after 5 min. Then, 2 mL of 1 M NaOH was added to the mixture after 6 min. The volume of the mixture was made 10 mL by immediately adding distilled water