Solutions

Dual Flow RI Detector

The dual flow design of the RI detector and the temperature controlled pumps of the EcoSEC High Temperature GPC System deliver precise flow rates at all temperatures, even when changes in environmental conditions occur, thus producing reproducible results sample after sample, day after day.

The intraday and day-to-day reproducibility of the EcoSEC High Temperature GPC System are shown in the figure below.

DualFlowRI_HT1.png

Reproducibility (intraday, n=6)
  R.T.:   CV 0.017%
  Area: CV 0.42%

Reproducibility (day to day, n=5)
  R.T.:   CV 0.047%
  Area: CV 0.71%

Column:

Mobile phase:
Flow rate:
Detector:

Temperature:
Injection vol.:
Sample:
TSKgel GMHHR-H (S) HT2, 13 µm, 
7.8 mm ID × 30 cm × 2
ODCB with 0.05% BHT
1.0 mL/min
RI (EcoSEC High Temperature
GPC System)
145 °C
300 µL
polystyrene (F-20), 0.02% 

The engineering design concepts of the EcoSEC High Temperature GPC System result in a high degree of reproducibility of retention times (Figure A) and molar mass determinations (Figure B). The coefficients of variation for retention time and weight-average molar mass, Mw, are well below 1% for successive injections.

DualFlowRI_HT2.png
Column:

Mobile phase:
Flow rate:
Detector:

Temperature:
Injection vol.:
Sample:
TSKgel GMHHR-H (S) HT2, 13 µm, 
7.8 mm ID × 30 cm × 2
ODCB with 0.05% BHT
1.0 mL/min
RI (EcoSEC High Temperature
GPC System)
145 °C
300 µL
polypropylene

Note: In addition to solvent flowing through the sample cell, in the EcoSEC High Temperature GPC System dual flow detector, a second pump also delivers solvent through the reference cell, thus providing a higher level of RI baseline stability.