Restek has introduced a manufacturing process that produces Plot columns with concentric stabilised adsorption layers, improving particle stability.
Traditional porous layer open tubular (Plot) columns are built with a 5-50 micron layer of particles adhered to tubing walls.
Because this layer of particles generally lacks stability, the columns must be used carefully to avoid particle release, which causes unpredictable changes in retention time and flow behaviour.
The new generation of Plot columns exhibits a constant flow behaviour and features improved mechanical stability, resulting in easier operation, better chromatography, more reproducible retention times, reduced spiking and longer column lifetimes.
This technology is currently applied to RT-Alumina Bond, RT-MSieve 5A, RT-Q-Bond, RT-QS-Bond, RT-S-Bond and RT-U-Bond columns.
For applications in which flow is important, such as with Deans switching, this new Plot column manufacturing process results in greater consistency in column-coating thickness and flow restriction.
Restek's flow restriction factor (F) allows users to evaluate flow-restriction reproducibility.
It is based on the retention time of an unretained compound and can be used to assess the degree of restriction of the column and to evaluate the reproducibility of the column-coating process.
This advance in Plot column technology is especially important for the petrochemical industry as it can help to achieve more efficient, reproducible analyses of permanent gases, solvents and hydrocarbons.