OMNISEC GPC/SEC System by Malvern Panalytical

"A very useful polymer characterization instrument. Very versatile as it gives the opportunity to obtain a range of information for the synthesized polymers (absolute molecular weight, dispersity, information about architecture) using only one calibration standard"

"Malvern instrument are always very reliable in reproduciblity, accuracy of the results. The instrument hardware are best quality which make the instrument robust and sustainable for long duration. Their user interface / software are also very good which make the work of interpretation of results, half done by itself (multi-angle light scattering with RI in GPC)."

"The OMNISEC Resolve+Reveal GPC system from Malvern is for sure the only system in the market with such kind of integrated triple detection system along with high accuracy. The best part is their low angle light scattering (LALS) which is at 7°. This provides very accurate MW determination without the requirement of any fitting in the Zimm plot since 7° is almost close to 0° when it comes to extrapolation. Another eye-catching feature is the Omnisec software which controls all the features of the GPC and the detectors in one window. This feature is lacking in other competitor machines, I would say. However, since nothing is perfect in this world, there are also some shortcomings with the Malvern Omnisec GPC system. For example, the lack of enough data from the point of view of solvents used for regular polymer characterization. Malvern is strictly following Polystyrene in THF as a standard for detector calibration, but in cases of another solvent (e.g. DMAc+LiBr), they simply have no data. On the other hand, they claim that the column compartment can hold up to 6 columns but it does not seem so. At max, it can hold 4 columns only."

"We use the OmniSEC system to analyze the molecular weight of various types of polymers, such as polyesters, polystyrenes and polyurethanes with molecular weight ranging from a few thousands up to a million. The machine has an intuitive user interface, and produces good, reliable and reproducible results. The columns are easily accessible which makes routine maintenance easy, and the Malvern tech support has always been ready to assist us whenever necessary. However, we have had some problems with the Malvern sales unit, as sometimes the delivery times for consumables has been delayed, invoices sent to the wrong places and lack of communication (which I think is especially crucial when things go wrong), and this is why I only give 3/5 for after sales care."

"Have been using the instrument for molecular weight determination of production and new material. Following the recommended procedures, instrument functions very well. Care must be taken not to introduce particles above 2um, and degassing of solvent is important. When switching between solvents specially aqueous and organic, taking extra time to go from low flow (0.1 mL/min) to higher flow rate (1 mL/min) eliminates many difficulties."

"Easy maintenance, especially for those familiar with the Varian system. However, warranty plan is advised for purchase - we had an issue with pump (leaking) within the first year and with a laser (LS) in the 3rd year (was replaced, very costly). Software is quite intuitive."

"System is generally rather easy to use. The SW is helpful, however more easy extraction of all collected data would be appreciated - reports in pdf are nice but exporting of data itself is not straightforward. The basic tools e.g. wrenches for exchange of column and filters, could be included with the system upon purchase - their price is minimal compared to the whole system, but is is annoying to look for the right ones in local shops. "Baseline monitoring" of longer than 4 hrs would be sometimes appreciated - e.g. to monitor the system overnight if needed."

"As expected, the system has a learning curve with the use of multiple detectors in series. Support has been great and has allowed us to learn the technique and be able to use and care for the instrument more effectively. Overall, the system is reliable and we are confident that it will provide us with accurate and reliable results."

"We have had a great deal of problems with the instrument. Electronic and application based. An earlier model of this line performs the analyses on our products with no problems as evidenced by the fact that we have been getting accurate data for quite some time yet using the same conditions and column. We find that the lenses on the light scattering detector cloud and we also have issues with baseline irregularity. We have found that the staff of Malvern are much more familiar with organic solvent systems than aqueous as evidenced by the lack of practical assistance in solving our issues."