The pump heads and solvent lines are maintained at a constant temperature within the range of ambient plus 10oC to 50oC, allowing the pumps to deliver exactly the same flow rate under any mobile phase condition. Most HPLC pumps do not compensate for volume changes as a function of temperature. The EcoSEC GPC system has a dedicated oven just for the pumps, thus ensuring the same volume of solvent delivered under any condition.
The first Figure below illustrates the superior baseline stability for the EcoSEC GPC system compared to a conventional GPC system when the temperature in the lab was changed by 3oC every few hours.
The last two Figures demonstrate very low RSD values for retention time and calculated molecular mass when repeated injections were made of narrow molecular weight polystyrene standards and a broad molecular weight vinyl chloride/vinyl acetate/vinyl alcohol terpolymer.
Room temperature effect on retention time
Reproducibility of retention time
Reproducibility of molecular weight
|