Author Archives: Kyle Williams


Published 15 Nov 2018

Can GPC/SEC determine if my sample is branched?

While talking to customers about their samples, a frequent topic that comes up is whether or not their samples are branched.  Fortunately, I work primarily with Malvern Panalytical’s gel permeation / size exclusion chromatography (GPC/SEC) product range, which in addition…READ MORE >

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Published 19 Sep 2018

Which light scattering detector is best for me?

Determining which gel permeation/size exclusion chromatography (GPC/SEC) system is best for your needs can be a daunting task. Even after you’ve decided to include a light scattering detector to obtain absolute molecular weight data you’re still left to choose between…READ MORE >

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Published 22 Aug 2018

What is a dn/dc value and why is it important for GPC/SEC?

The most common detector in any GPC/SEC instrument is a refractive index (RI) detector.  There are multiple reasons for this, but the most important is because the difference in refractive index between that of a sample solution and that of…READ MORE >

Published 24 Jul 2018

Why does my viscometer signal have a negative peak?

If you’ve ever analyzed GPC/SEC data collected on your OMNISEC or TDA 305 instrument that included a viscometer detector, you might have observed and wondered about a negative peak that elutes in the viscometer signal long after the sample peak. …READ MORE >

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Published 12 Jul 2018

Why do I need a standard if I have a GPC/SEC system with a light scattering detector?

To many people, obtaining molecular weight information from GPC/SEC analysis involves a lengthy calibration process.  A series of standards of known molecular weight are analyzed and a calibration curve based on the standards’ retention volume is generated.  This can be…READ MORE >

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