Why do compounds have different Rf values in different solvents?

Why do compounds have different Rf values in different solvents?

In general, low polarity compounds have higher Rf values than higher polarity compounds. In general, the adsorptivity of compounds increases with increased polarity (i.e. the more polar the compound then the stronger it binds to the adsorbent). The eluting power of solvents increases with polarity.

Why would Rf values be different?

Rf values and reproducibility can be affected by a number of different factors such as layer thickness, moisture on the TLC plate, vessel saturation, temperature, depth of mobile phase, nature of the TLC plate, sample size, and solvent parameters.

How do you compare Rf values?

In thin-layer chromatography, the retention factor (Rf) is used to compare and help identify compounds. The Rf value of a compound is equal to the distance traveled by the compound divided by the distance traveled by the solvent front (both measured from the origin).

Does Rf value depends on solvent?

Solvent impact on retention factors: Since the solvent carries the analyte up the TLC plate, the solvent used also will affect the value of the component retention factor. The solvent mixture also has effects on the Rf value which is depending on the proportion of each solvent.

Does Rf value depend on solvent?

Since the solvent carries the analyte up the TLC plate, the solvent used also will affect the value of the component retention factor. The solvent mixture also has effects on the Rf value which is depending on the proportion of each solvent.

Would you expect similar Rf values if you used a different solvent?

If two substance have the same Rf value, they are likely but not necessarily the same compound. If they have different Rf, they are definitely different compounds.

Does the solvent affect the Rf value?

Retention factor values in thin layer chromatography are affected by the absorbent, the solvent, the chromatography plate itself, application technique and the temperature of the solvent and plate.

Why is the Rf value always less than 1?

By definition, Rf values are always less than 1. An Rf value of 1 or too close to it means that the spot and the solvent front travel close together and is therefore unreliable. This happens when the eluting solvent is too polar for the sample.

Why different amino acids have different Rf values?

The different amino acids move at differing rates on the paper because of differences in their R groups. Rf is simply the distance the biomolecule moved through the filter paper divided by the distance the solvent moved through the paper.