Jennivee Chua

6 Questions 2 Answers 0 Followers

Questions related from Jennivee Chua

Why does sample turn red even without AlCl3 for NaNO2 method for TFC assay?

I use the NaNO2+AlCl3 method to quantify the TFC of cacao extracts. Sample+NaNO2+AlCl3 then NaOH. As sample blanks, I use the same reagents but replace AlCl3 with water. I notice that when I add...

06 April 2025 836 0 View

How can you analyze a sample in Tween 80 solution in HPLC?

I have a plant extract in 2.5 to 10% Tween 80. I intend to analyze it via HPLC to quantify catechin. While literature often uses cloud point extraction to concentrate the surfactant-rich phase, I...

24 January 2025 2,002 0 View

Is it possible to use catechin standard for AlCl3-potassium acetate total flavonoid assay?

I used quercetin standard for TFC using AlCl3 and potassium acetate. While I was able to establish my calibration curve at 415nm, there was no color change for my sample. I even tried using...

11 October 2024 8,504 2 View

What are the parameters to sufficiently remove ethanol using a rotavap in preparation for freeze drying?

I will try to dry a 50% ethanol solution to obtain my dry extract. When I tried to have a 3rd party remove the solvent from my 20mL sample using purely the rotavap, they told me there was...

26 April 2024 5,259 1 View

How would you categorize waste after TPC determination per RA6969?

I will be determining the total phenolic content using Folin Ciocalteu assay. However, I am having difficulty in determining the category of the waste generated. In previous researchers, they...

19 March 2024 458 0 View

Experience in vacuum removal of water and ethanol?

I am trying to dry my extract using a make-shift vacuum setup with a flask (containing the sample), a solvent trap and a vacuum pump. My heat source would either be a water bath. Can anyone share...

23 February 2024 2,468 1 View