Summary: Batch (Determine dn/dc) using Optilab rEX:
The determination of dn/dc for a specific sample in a solvent is done by manually
injecting several concentraions (using syringe pump) of the sample (4-5 concentrations 1-
9 mg/mL = 0.001-0.009 g/mL) :
1. 0.00095 g/mL
2. 0.002 g/mL
3. 0.006 g/mL
4. 0.0095 g/mL
The solvent used to dissolve the sample should also be injected before and after samples.
When you have run the experiment, define the peaks and the concentration of each
sample. These concentrations have to be very precise. In the "dn/dc from peak"
procedure, the dn/dc value, errors, and graph are displayed.
- Turn ON OPTILAB rEX turn on nitrogen gas if you need to measure below
- Open Astra program.
- File- New- Experiment from Template Optilab rEX dndc CREATE
- In Experiment Open Configuration (RI batch) Optilab rEX Solvent
- Choose solvent from the list or choose solvent with similar parameters like DMF-
Benzene or choose Custom Solvent (for example- DMF: Refractive Index = 1.43,
viscosity = 0.944 g/mL and Rayleigh Ratio (685 nm) = 9.82 10-6, Refractive