Why Is The Retardation Factor Important?

What is Rf value and what is its significance in chromatography?

The Rf value is defined as the ratio of the distance moved by the solute (i.e.

the dye or pigment under test) and the distance moved by the the solvent (known as the Solvent front) along the paper, where both distances are measured from the common Origin or Application Baseline, that is the point where the sample is ….

What does the RF value tell you?

The Rf values indicate how soluble the particular pigment is in the solvent by how high the pigment moves on the paper. Two pigments with the same Rf value are likely to be identical molecules. Small Rf values tend to indicate larger, less soluble pigments while the highly soluble pigments have an Rf value near to one.

Which pigment has the highest RF value?

PigmentRf value rangeRelative positionLutein0.22-0.28Below, or almost at the same level of, the highest greenViolaxanthin0.13-0.19Below, or almost at the same level of, the highest greenNeoxanthin0.04-0.09Below, or almost at the same level of, the highest green

What is the importance of finding the retardation factor in chromatography?

It can provide corroborative evidence as to the identity of a compound. If the identity of a compound is suspected but not yet proven, an authentic sample of the compound, or standard, is spotted and run on a TLC plate side by side (or on top of each other) with the compound in question.

How do you calculate retardation factor?

The RF value (retardation factor) of a zone is the ratio of its migration distance to that of the mobile phase front. RF = MD/zf.

What factors affect the RF values?

Retention Factor 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. These effects normally cause an increase in Rf values.

What does eluent mean?

Definition. noun, plural: eluents. A substance that separates and moves constituents of a mixture through the column of a chromatograph. Supplement.

How do you interpret RF values?

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).

What is retardation factor value?

The fundamental parameter used to characterize the position of a sample zone in a thin-layer chromatogram is the retardation factor, or RF value. It represents the ratio of the distance migrated by the sample compared to the distance traveled by the solvent front, and for linear development is given by. [4]

What is the principle of chromatographic separation?

Chromatography is based on the principle where molecules in mixture applied onto the surface or into the solid, and fluid stationary phase (stable phase) is separating from each other while moving with the aid of a mobile phase.

What is retardation factor in chromatography?

Learn about this topic in these articles: The retardation factor is defined as the distance from the original sample spot that the component has moved divided by the distance that the mobile phase front has moved and is… In chromatography: Development chromatography.

Why is RF 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.

What does a high RF value mean?

A high Rf (Ie 0.92) would refer to a substance that is very non-polar. Ie that substance moved a 92% of the entire distance the solvent traveled. A low Rf value (0.10) would refer to a substance that is very polar.

How is RF value useful?

Rf value stands for the retardation factor value. It tells us how far the unknown pigment traveled in relation to the distance the solvent traveled. The Rf value is useful for scientists because it allows scientists to identify the pigment by comparing its Rf value to that of a known standard.

Is a higher Rf value better?

The stronger a compound is bound to the adsorbent , the slower it moves up the TLC plate. Non-polar compounds move up the plate most rapidly (higher Rf value), whereas polar substances travel up the TLC plate slowly or not at all (lower Rf value).