A technical study from TESTA Analytical demonstrates the importance of continuous monitoring of current flow rate in GPC/SEC experiments.
Flow rate is one of the most important parameters in any liquid chromatography system, it determines retention time or volume and therefore has a major influence on reproducibility. In the study, the TESTA Analytical Liquid Chromatography Flowmeter is demonstrated as providing a valuable tool for continuous, non-invasive measurement of flow rate in GPC/SEC systems.
Researchers investigated the effect of a +/- 1% deviation in flow rate on results for an unknown sample determined with both a standard calibration and a universal calibration. The small variation in flow rate was selected as it might arise due to backpressure in a typical GPC/SEC system which is often below the detection limit of the pump pressure transducer and is thus undetectable with on-board means. The investigation was conducted by running a sample right after calibration, performing calculations and subsequently manually changing the flow rate parameter used for calculation. This was then repeated for a second sample using a viscosity detection and universal calibration.
The reported results from the study showed that a 1% deviation in flow rate resulted in a change of more than 20% in calculated molecular weight results, underlining the necessity for a suitable method of constant monitoring of current GPC/SEC flow rates and correction of running chromatogram.
The HPLC flowmeter range from TESTA Analytical is compatible with all common solvents. Powered via a USB connection, it features a high-resolution, non-invasive thermal flow sensor that is both extremely accurate and sensitive. Each instrument is supplied with an easy-to-use PC based App that allows users to continuously record, and store measured flow rate data from a liquid chromatography system. Current flow rate is displayed on the devices integral high-resolution OLED display. For further information on the liquid chromatography flowmeter for GPC/SEC please visit https://www.testa-analytical.com/gpc-sec-chromatography.html. To request a copy of the technical study please contact Testa Analytical on +49-30-864-24076 or info@testa-analytical.com.
