Using standard silica HPLC columns, it can be shown that as the flow rate increases, column efficiency decreases. The relationship between flow rate and column efficiency can be plotted on a Van Deemter plot which can be used to determine the optimum mobile phase flow rate. A faster flow rate through the column will produce a faster analysis time. Mobile phase flow ratesĪnother technique to speed up HPLC analysis is to increase the mobile phase flow rate.

If the pressure increases too much, standard HPLC instruments might not be capable of handling the pressure changes. Reducing particle size to increase efficiency also has an effect on the backpressure in the column because the pressure is inversely proportional to the square of the particle size. If the column length is reduced to increase the speed of analysis and the resolution becomes too low, the stationary phase particle size will have to be reduced to increase efficiency and resolution back to acceptable levels.

inversely proportional to the stationary phase particle size.

proportional to column length a longer column is more efficient.

The resolution of a column is measured by its efficiency - and the more efficient a column is the better the resolution. The question raised is if the column length is shortened to increase throughput, how can the resolution of the column be maintained? If the column length is reduced, the number of theoretical plates in the column will be correspondingly reduced and therefore the resolution of the HPLC system. This has the effect of reducing the run time - and so the throughput of the system is increased. One of the simplest ways of speeding up an HPLC system is to reduce the column length.

Peak resolution has to be considered if changes are made to the HPLC system to speed up the analysis of multiple samples- fast, inefficient analysis defeats the object of increased throughput if the chromatography runs have to be repeated.

It is important to have an efficient column, as this will produce a good separation of the sample components in the chromatogram in other words, acceptable peak separations. The ability to speed up a high performance liquid chromatography (HPLC) run has obvious benefits by reducing analysis time and therefore costs.

How much hplc analysis