Multi-Angle Light Scattering Detection (MALS) results in the measurement of absolute molecular weight which is independent from the column calibration. The amount of light scattered (measured by MALS) is proportional to the molar mass of the polymer (M), the concentration (c) of the polymer, and the square of specific refractive index increment (dn/dc). Special procedures must be taken if the sample absorbs or if the sample fluoresces with exicitation at the wavelength of the laser (663.1 nm).
The ViscoStar detector measure specific viscosity. When coupled with a concentration detector as the Optilab rEX, it can be used to derive the intrinsic viscosity. The intrinsic viscosity, in turn can be used to derive the hydrodynamic radius and shape information about molecule in solution. The air-cooled Peltier allows to control temperature from 4-60oC. Operation below ambient temperature requires the flow of dry gas into the temperature - controlled environment.
Pump: Waters Alliance HPLC System, 2695 Separation Module.
GPC Columns: 2 Agilent PolyPore, 5 um, 300 x 7.8 mm + guard
Wyatt DAWN HELEOS-II (laser 663.1 nm).
Wyatt Optilab rEX (RI).
Waters 2996 Photodiode Array Detector (PDA).
Solvent: chloroform with 0.25% TEA
Flow rate = 1 ml/min.
Injection: 100 µL.
MRL, Room 1052
Instrument Information and/or Manual:
|GPC MALS Manual||86.4 KB|
Please contact Rachel Behrens (rachel [at] mrl [dot] ucsb [dot] edu) to schedule training. Please read the MANUAL before scheduling training.