Accurate molecular weight and structure by GPC

Available from Viscotek are a range of proprietary viscosity and light scattering detectors for gel permeation chromatography (GPC) that enable determination of even complex sample molecular weight (MW) and structure.

In GPC molecules are separated according to their hydrodynamic volume.

The technique is used traditionally with refractive index (RI) or ultraviolet (UV) detectors to determine MW and MW distribution.

However because the majority of polymers and proteins to be analysed are different from the standards used for conventional calibration such methods rarely achieve accurate MW determination. Viscotek's latest generation of viscosity and low angle light scattering (Lals) detectors present a versatile and high performance way to overcome the limitations of conventional GPC. Unlike multi-angle light scattering techniques that can only determine molecular weight by extrapolation, Viscotek Lals measures molecular weight directly and thus is inherently more accurate.

Incorporating patented optical technology that will effectively operate at an angle of only 7deg the Lals detector represents a major breakthrough in light scattering technology. Providing the intrinsic viscosity of a polymer or protein directly, Viscotek's patented GPC-Viscosity detectors can be used to measure molecular size distribution and structural differences over a wide MW range.

Through combining the advantages of both of these proprietary detectors Viscotek is uniquely able to offer in a single system the ultimate polymer and protein characterisation technique - GPC triple detection. Using the Viscotek GPC-TD system, MWs can be accurately determined by Lals and valuable structure and size information gained from the viscosity detector.

In addition, this powerful combination makes it possible to determine and differentiate between aggregates and microgels as well as to analyse low MW and/or low dn/dc polymers.