The EcoSEC GPC system features dual flow refractive index detection for enhanced baseline stability, unaffected by significant changes in temperature and atmospheric pressure. RI detectors measure the difference in refractive index between a sample and a reference cell.
Based on the dual flow design, the solvent flowing through the reference cell, and high performance thermostatisation, the RI detector provides unmatched baseline stability.
Most RI detectors are of the single flow type, in which the reference cell is statically filled with solvent rather than the solvent flowing through the cell, as in the dual flow design. In a single flow design, the properties of the solvent in the reference cell slowly change over time. Since the solvent flows through the reference cell in a dual flow RI detector, the changes over time become insignificant. The figures below demonstrate that the improvement in baseline stability obtained with a dual flow detector far outweighs the cost of adding a second pump.
Baseline comparison:
Dual (EcoSEC GPC system) vs. Single (conventional GPC systems) flow RI detectors
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In each Figure, five chromatograms are overlayed, demonstrating the superior stability of the RI baseline in the EcoSEC GPC system.
Note: In addition to solvent flowing through the sample cell, in the RI-8320 dual flow detector, a second pump also delivers solvent through the reference cell, thus providing a higher level of RI baseline stability.
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Dual flow structure |
| Unique signal to noise ratio |
| System: |
Bryce-type double path or double flow |
| Light source: |
Tungsten lamp |
| Refractive index range: |
1.00 to 1.80 |
| Range (FS): |
64,256×10-6 RIU/1 V |
| Response: |
0.5, 1.0, 3.0 s/td |
| Flow cell: |
Made of quartz glass
(Volume: 2.5 μL, Withstand pressure: 0.5 MPa) |
| Dynamic range: |
5×10-4 RIU |
| Noise: |
2×10-9 RIU (THF sealed in, Response: 3.0 s) |
| Drift: |
1×10-7 RIU/h (THF, liquid supply at 1.0 mL/min) |
| Temperature control: |
OFF, 35, 40, 45ºC |
| Safety mechanism: |
Liquid leakage sensor
Circuit shutdown by thermal fuse |
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