Hello dear scientists,

I am following the method of L  Wei, et al 2015 for the determination of total Triterpenoids contents but there is no information about the mechanism of reactions when we add the reagents to the extract. Can some one please tell me or share an information about this method. I am really confused as whether i am doing it correctly or not? Method is: I take 100 micro-liter of extract and then I add 500 micro-liter (5% W/V) Vanillin Acetic Acid solution. After that I add 900 micro liter of sulphuric acid and I get BROWNİSH color. After incubating it at 70C for 30 minutes then İ dilute it up to 5ml with Acetic acid and check the absorbance at 573 nm by using spectrometer. I am also attaching the concerned research article below for your kind information.

so can anyone share any information about this mechanism?

your answer would be highly appreciated.

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