pn01.jpg (7672 bytes)The Model 300 triple detector array for gel permeation chromatography/size exclusion chromatography technology can be used for characterizing natural and synthetic polymers. Its concentration detector, viscometer and light scattering detector act in concert with each detector to provide complementary but different information.
     The integrated detector TDA module consists of three detectors: a light scattering detector, a differential refractometer detector, and a four-capillary balanced bridge viscometer. The array is designed as a module that plugs into the heated oven compartment and can be removed for maintenance. By combining three detectors in a single experiment, triple detection allows the determination of absolute molecular weight, intrinsic viscosity and molecular size. It also provides information on the conformation, structure, branching and aggregation characteristics of the sample.
      Light scattering has limitations and cannot be used for samples of low molecular weight, poor dn/dc or varying dn/dc. Light scattering also has limitations in determining molecular size, and cannot be used at less than 12-15nm. In these cases, the viscometer is used to measure molecular weights to the oligomer level and molecular size to less than 1nm. Viscotek