Question

(1-propanol, 2-propanol, methanol, 95% ethanol, acetone, ethyl acetate, hexane, and toluene) what will happen if each one its mixed separately with spinach extract into a TLC plate

Answer 1

Spinach mainly contains chlorophyll and carotene as pigments. since the extraction is based on polarity of the compound. As silica and alumina serves as stationary phase in TLC due to electropositive character of the aluminum or silicon and the electronegative oxygen. Therefore, the more polar the molecule to be separated, the stronger is the attractive force to the stationary phase. So, the polar stationary phase will more strongly attract polar molecules  and the more slowly the molecules will move. Nonpolar molecules will have a lower affinity for the stationary phase and will remain in the solvent longer. As we know chlorophyll is a more polar molecule than carotene as chlorophyll has a greater number of double bonds, and it possesses a far greater number of electronegative elements. These structural differences mean that chlorophyll, because of its greater polarity, will be more strongly adsorbed onto the alumina than β-carotene would. so chlorophyll is less mobile than carotene in TLC. As we know, polar solvent would cause the pigments to move up the plate more rapidly as compared to non polar solvents. In the given solvents, the order of polarity is methanol>ethanol>propanol>acetone>2-propanol>ethyl acetate>toluene>hexane. So the place will move rapidly with methanol and solwly with hexane