Because of the large number of compounds classes involved in such plant extract ,it's difficult to identifying such compounds based only on UV-Vis spectroscopy. More than one compound may exhibit an absorption in the same region or absorption of such compounds may be overlapping . Based on spectrum of extract, you can detect existence of compound class according to it's peak that relates with an electronic transition. To identify the compounds ,firstly, you must to separate extract components via chromatographic techniques and then you can use spectroscopic techniques to achieve identification.

Dear Afrina,

what do you mean with " constructed"? Do you mean "obtained" with your spectrometer.

You obtained 4 peaks!! Please send us (the answerers) a picture of your spectrum.

Give please some infos :

- About the E-value (must be between 0-1 ) used for your measures

-about the solvent used for the extraction . The product obtained after evaporation was solved in was for UV-Vis????

(pure water, Ethanol for spectroscopy as.o..).

- What a kind of cuvettes and spectrometer?? (single or dual beam or diode arrays..)

- Every solvent for UV-Vis has cut off .

- You have a chromophoric system or more for these 4 peaks.

- Without IR, NMR , MS , GC-MS a.s.o.....for the structure elucidation , you cannot obtain valuable infos only with UV-Vis for the different compounds as mentioned in your question.

-With Thin Layer Chromatography (TLC) , you can see the various compounds and you can obtain the pure compounds with C.C. (Column Chromatography) after elution.

please obtain these book and references as examples:

https://link.springer.com/book/10.1007/978-3-642-77477-5

Article Determination of saffron (Crocus sativus L.) components in c...

Article Application of a UV–vis detection-HPLC method for a rapid de...

There are a plenty of valuable papers in the web. Please search in Google or Google Scholar.

JRG

Because of the large number of compounds classes involved in such plant extract ,it's difficult to identifying such compounds based only on UV-Vis spectroscopy. More than one compound may exhibit an absorption in the same region or absorption of such compounds may be overlapping . Based on spectrum of extract, you can detect existence of compound class according to it's peak that relates with an electronic transition. To identify the compounds ,firstly, you must to separate extract components via chromatographic techniques and then you can use spectroscopic techniques to achieve identification.

it depends on what kind of compounds are you focusing , if you want to isolate flavonoids they have certain uv absorption if you want coumarin usually its around 300nm , and so on .

You cannot. First you need to separate them using LC/Column. If you have standards then use HPLC to separate and identify them, else use LC-MS/MS