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In chromatography, the retardation factor (R) is the fraction of an analyte in the mobile phase of a chromatographic system. [1] In planar chromatography in particular, the retardation factor R F is defined as the ratio of the distance traveled by the center of a spot to the distance traveled by the solvent front. [2]
Retention distance, or R D, is a concept in thin layer chromatography, designed for quantitative measurement of equal-spreading of the spots on the chromatographic plate and one of the Chromatographic response functions. It is calculated from the following formula:
The [N 1/2 /4] term is the column factor, the [(α-1)/α] term is the thermodynamic factor, and the [k 2 '/(1+k 2 ')] term is the retention factor. The 3 factors are not completely independent, but they are very close, and can be treated as such. So what does this mean?
Chromatographic peak resolution is given by = + where t R is the retention time and w b is the peak width at baseline. The bigger the time-difference and/or the smaller the bandwidths, the better the resolution of the compounds.
The Purnell equation is an equation used in analytical chemistry to calculate the resolution R s between two peaks in a chromatogram. [1] [2]= (′ + ′) where R s is the resolution between the two peaks
In gas chromatography, the Kovats retention index (shorter Kovats index, retention index; plural retention indices) is used to convert retention times into system-independent constants. The index is named after the Hungarian-born Swiss chemist Ervin Kováts , who outlined the concept in the 1950s while performing research into the composition ...
The retention factor (R ƒ) may be defined as the ratio of the distance travelled by the solute to the distance travelled by the solvent. It is used in chromatography to quantify the amount of retardation of a sample in a stationary phase relative to a mobile phase. [2] R ƒ values are usually expressed as a fraction of two decimal places.
The retardation factor (R f), or retention factor, quantifies the results. It is the distance traveled by a given substance divided by the distance traveled by the mobile phase. [citation needed] Development of a TLC plate. Spots that appear purple separate into red spots and blue spots.