The Two-Dimensional Solvent Gradient Interaction Chromatograph (SGIC 2D) instrument performs a fractionation of the polymer according to composition by solvent gradient HPLC technique in adsorption mode followed by a second separation by Gel Permeation Chromatography (GPC/SEC) of the fractions eluted from the first dimension.
The instrument is fully automated and the whole process is controlled by the virtual instrumentation software. Once the vials with the dry samples are placed in the autosampler external tray, the instrument will take care of the filling with solvent, dissolution with gentle shaking, optional filtration in-line, and injection into the HPLC column. Then the solvent gradient process is started and the resulting fractions are injected towards the GPC/SEC columns.
The detection is done by standard infrared detector at the exit of the GPC/SEC columns, which provides a linear response and an outstanding stability, overcoming this way the limitations in detection found in single dimension SGIC due to the varying mobile phase composition.
At the end of the analysis the two-dimensional distribution relating molar mass and composition is obtained. This combined information is often required for comprehensive characterization of complex materials. The SGIC 2D is specially suitable for the analysis of samples of low crystallinity or complex polarity distribution, when classic cross fractionation technique based on crystallization (TREF GPC) does not provide the desired separation.
Polymer Char’s analytical SGIC 2D instrument is a practical alternative to preparative fractionation methods, which are sometimes tedious and time consuming. The composition - molar mass interdependence is now measured in hours instead of days, with limited solvent consumption and no manual intervention, in an intrinsically safe setup.