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The van Deemter equation is a hyperbolic function that predicts that there is an optimum velocity at which there will be the minimum variance per unit column length and, thence, a maximum efficiency. The van Deemter equation was the result of the first application of rate theory to the chromatography elution process.
The main application of size-exclusion chromatography is the fractionation of proteins and other water-soluble polymers, while gel permeation chromatography is used to analyze the molecular weight distribution of organic-soluble polymers.
A faster flow rate of the eluent minimizes the time required to run a column and thereby minimizes diffusion, resulting in a better separation. However, the maximum flow rate is limited because a finite time is required for the analyte to equilibrate between the stationary phase and mobile phase, see Van Deemter's equation.
The same equation applies in chromatography processes as for the packed bed processes, namely: = In packed column chromatography, the HETP may also be calculated with the Van Deemter equation. In capillary column chromatography HETP is given by the Golay equation.
The quantitative parameters and equations which determine the extent of performance of the chromatographic system. The parameters are largely derived from two sets of chromatographic theory: plate theory (as part of partition chromatography), and the rate theory of chromatography / Van Deemter equation. Of course, they can be put in practice ...
Jan Jozef van Deemter (31 March 1918 – 10 October 2004) was a Dutch physicist and engineer known for the Van Deemter equation in chromatography. [ 1 ] [ 2 ] [ 3 ] He obtained his doctorate in physics from the University of Amsterdam in June of 1950.
The Rodrigues equation is an extension of the Van Deemter equation used to describe the efficiency of a bed of permeable (large-pore) particles. [4] The equation is: = + + where HETP is the height equivalent theoretical plate
Two-dimensional chromatograph GCxGC-TOFMS at Chemical Faculty of GUT GdaĆsk, Poland, 2016. Two-dimensional chromatography is a type of chromatographic technique in which the injected sample is separated by passing through two different separation stages.