Plants or food sources have many secondary metabolites (eg. alkaloids, saponin, stigmasterol , lupeol, quercetin, rutin etc.) that have many pharmaceutical properties. So, however, I can determine these phytochemicals from the experimental samples?
So many methods or techniques for determination of secondary metabolites or phytochemicals like JPTLC, HPLC, GC OR GCMS, LCMS and other traditional methods.
As everybody knows plants are the library of diverse type of phytochemicals and number of methods for the estimation of phytochemical /intermediate compounds are present as mentioned in discussion. But firstly you decide what type of phytochemical (alkaloids, glycosides, tannin's, flavanoids, carotenes, etc.) of your interest, and you want to determine in the plant sample. Determining all phytochemical ingredient present in the plant run chromatogram (HPLC) and got major and minor phytochemical present in the sample.
There are some of the traditional methods in china and India for determining the secondary metabolites/constituents as the oldest references of the medicinal plants. But they are used low. Nowadays, in order to determine the phytochemical analysis of the medicinal plants are used the commonplace methods/techniques such as JPTLC, HPLC, HPTLC, TLC, GC, GCMS, LCMS, GPC, NMR and so on.
Mr. Rahaman, there are already well developed identification tests or qualitative tests for the class or group of phyto-chemicals/ secondary metabolites present in the selected raw botanical ingredients as above said by AK Meenaji, Rocio and PK Verma. Based on the interest of your phyto-compounds to identify or to quantify is the key to choose your method and technique to use which instrument based the nature of the selected secondary metabolite or Phyto-compounds as above described. Example if volatile oils/ contents is the interest, GC-MS method should be used among above mentioned methods in above answered.