Mass Spectrometry

Detecting and controlling mutagenic impurities in pharmaceuticals is challenging. What is ICH M7 and what do you need in your analytical toolbox?

When disruptive technology comes along, it can be hard to defend the technique under attack for some applications – even if we have embraced it for decades.

What’s new in business this month?

Is a new and improved mass spectrometer the “Holy Grail” of chemical sensing?

Using PTR-MS to track the chemistry of group emotion

The world is in serious trouble when “Photoshop” is added as a major skill on the curricula vitae of scientists.

In this application note, a mixture of four proteins was characterized in a single SEC measurement using multiple detectors. The generally consistent response to the RI to proteins makes it a useful total protein concentration detector, while the UV detector can be used to measure the concentration of individual proteins when the extinction coefficient is known. This is particularly useful for proteins that elute in the solvent peak making RI measurements unreliable. Finally, light scattering measurements allow each peak to be identified by its molecular weight.

The ideal solvent for a material may not provide a sufficient refractive index difference for light scattering detection. This example of a biodegradable polymer shows how SELS is used to increase dn/dc to give enhanced detection sensitivity

In this application note, a purified polyclonal antibody (IgG) is separated using Size Exclusion Chromatography (SEC) and characterized using the Viscotek SEC-MALS 20, allowing calculation of molecular weight and radius of gyration (Rg).

Then & Now, with Katie Banaszewski, Method Development Scientist III at Now Foods, Bloomingdale, Illinois, USA.