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In normal-phase TLC, the stationary phase is polar. Silica gel is very common in normal-phase TLC. More polar compounds in a sample mixture interact more strongly with the polar stationary phase. [citation needed] As a result, more-polar compounds move less (resulting in smaller R f) while less-polar compounds move higher up the plate (higher R ...
Polar water molecules are held inside the void space of the cellulose network of the paper. The difference between TLC and paper chromatography is that the stationary phase in TLC is a layer of adsorbent (usually silica gel, or aluminium oxide), and the stationary phase in paper chromatography is less absorbent paper.
The effect of steric hindrance on interaction strength allows this method to resolve (separate) structural isomers. [citation needed] The use of more polar solvents in the mobile phase will decrease the retention time of analytes, whereas more hydrophobic solvents tend to induce slower elution (increased retention times).
Even non-polar bonded silicas have been used with extremely high organic solvent composition, thanks to the exposed patches of silica in between the bonded ligands on the support, which can affect the interactions. [4] With that exception, HILIC phases can be grouped into five categories of neutral polar or ionic surfaces: [5]
When comparing a polar and nonpolar molecule with similar molar masses, the polar molecule in general has a higher boiling point, because the dipole–dipole interaction between polar molecules results in stronger intermolecular attractions. One common form of polar interaction is the hydrogen bond, which is also
Reversed-phase liquid chromatography (RP-LC) is a mode of liquid chromatography in which non-polar stationary phase and polar mobile phases are used for the separation of organic compounds. [ 1 ] [ 2 ] [ 3 ] The vast majority of separations and analyses using high-performance liquid chromatography (HPLC) in recent years are done using the ...
High-performance thin-layer chromatography (HPTLC) serves as an extension of thin-layer chromatography (TLC), offering robustness, simplicity, speed, and efficiency in the quantitative analysis of compounds. [1] This TLC-based analytical technique enhances compound resolution for quantitative analysis.
An increase in solvent polarity decreases the rates of reactions where there is less charge in the activated complex in comparison to the starting materials; A change in solvent polarity will have little or no effect on the rates of reaction when there is little or no difference in charge between the reactants and the activated complex. [6]