It all depends. How was your sample extracted? If you extracted with hexanes, then you only have the lipophilic compounds in your sample. That means that you want a non-polar solvent. If you extracted with water, then you need a polar solvent. Under any circumstances, you will find that rarely do you get good TLC results from a single solvent. Invariably, some compounds will stick at the origin and others will move with the front. That is why it is better to use multiple solvents to get the most information.
We have a system which has been established in our lab comprising of solvent systems ranging from polar (Ethyl acetate: Methanol: water) to intermediate polarity (Chloroform: Ethyl acetate: formic acid ) to non-polar (Benzene: Ethanol: Ammonia).
Thanks all for your contribution. The compounds present are Tanins (+), Saponins (++), Glycosides (++), Alkaloids (++), Terpenoids (++), Phenol (+). I was trying out different solvents as suggested above.
labelled 1: Ethylacetate: methanol: acetic acid: water (8:2:0.5,0.5).
labelled 2: Ethylacetate: methanol: water (8:1:1)
labelled 3: Ethylacetate: chloroform: water (7:2:1)
labelled 4: Methanol: acetic acid: water (7:2:1)
labelled 5: N-hexane: chloroform: water (8:1:1)
labelled 6: N-hexane: methanol: water (7:2:1)
labelled 7: N-hexane: acetic acid: water (8:1:1)
labelled 8: Ethylacetate: N-hexane: water (8:1:1)
labelled 9: Ethylacetate: chloroform: water (6:2:2)
labelled 10: Ethylacetate: N-hexane: water (6:2:2)