Identification of phenolic compounds from a given chromatogram?

I tried some of them but hard to get one that is free to download and work on MacBook.

Hi everyone, I synthesized several materials, metal oxides composited with graphene oxide or reduced graphene oxides. In brief, metal oxides first composite with graphene oxide (MGO), then with increased amount of reduction agent, we can get a series of metal oxide/reduced graphene oxide composition: MRGO-1, MRGO-2, MRGO-3, MRGO-4 (the amount of reduction agent is continuous increased from MRGO-1 to MRGO-4). The resulted FTIR curves in the attachment picture.

In contrast to GO, the typical C=O absorption bands at 1723 cm-1 of MGO and MRGO almost disappear, suggesting that the formation of the weak interaction in Metal cations--O–C, which leading to the emerging of the enhanced C–O at 1200 cm-1 instead of weak C=O. So, we can see that there is a weak peak of GO at 1200 cm-1, but became relatively stronger in MRGO-1, MRGO-2, MRGO-3. It makes sense, because the metal cations should connect to some kind of groups on the surface of GO to form the composition. However, for MGO, there is no peak at 1200 cm-1 but appear a new peak at 1330 cm-1 which also corresponding to C-O bond, how to explain this peak shift?

MGO: 1330 cm-1, C-O bond

MRGO-1, MRGO-2, MRGO-3: 1200 cm-1, C-O bond      

Folin Ciocalteu assay was done for TPC and AlCl3 colorimetric method was used for TFC. Can the lower total phenolic content be due to the free or bound phenolic compound which present in plant extract?

Experiment:

Weight of sample: 282g

Weight after extraction: 38g

Amount used in FC assay: 300uL used per reaction at (1mL/mg concentration)

GAE equivalent value: 0.1008

How can I calculate the total phenolic content to express as (mg GAE/g extract)?

Thank you in advance.

I am looking for an unconventional way to determine the total phenolic content of my samples. I am having difficulties because one of the reagents of my experiment (bile) is interfering in the Folin-Ciocalteu assay. I appreciate any help! Cheers

Column chromatography is time consuming task and the yield is normally low.

Experiment:

Weight of sample: 20g

Weight after extraction: 7.83 g

The crude extracted 7.83 g  were dissolved in 40 ml methanol>

Amount used in FC assay: 300µL of crude extract mixed with 600µL of

FC reagent(10%)  and 2.4 mL of sodium bicarbonate(700mM). Total volum was 3.3 mL

y = 0.0398x - 0.0006 , R² = 0.9971

GAE equivalent value: 56.088 mg/ml

How can I calculate the total phenolic content to express as (mg GAE/g extract)?

Thank you in advance.

Hello,

I am using the folin-ciocalteu method in order to quantify the Total Phenolic content of a plant extract.

I am using 0.5 ml of my extract + 2.5 ml of F-C reagent (diluted 10 times) and 2.5 ml of Na2CO3 (7.5%).

My problem is that when I add the Na2CO3, the solution turns instantly to dark blue so when I read the absorbance on the spectrophotometer, it goes directly to 4 (the max).

I diluted my sample 100 times and still have the same problem.

Any suggestions ?