Size exclusion chromatography of dextrans and pullulans with light scattering, viscosity and RI detection

With the introduction of multi-angle laser light scattering (MALLS)photometer, a potentially more powerful detection technique was made available. It was the objective of this work to characterize pullulans and dextrans in order to assess the performance of the size exclusion chromatograph with MALLS, viscosity and refractive index (RI)detectors. IT was anticipated that with the combination detectors, the performance of one detector could be effectively checked against that of the other. a SEC equipment was set up with light scattering, viscosity, and RI detectors. The ?Mw?'s by L.S. and universal calibration agreed very well with expected values for the low polydispersity pullulans and reasonably well for the broad MWD dextrans. The Rg (L.S.)agreed well with theoretical Rg for values above 10 nm, and scaling laws for whole polymers were in reasonable agreement with expected values. In conclusion, triple detection SEC proved to be a powerful and time saving technique for characterizing water soluble polymers absolutely, and confirming the values as well.