What should I check if the Mn, Mw, and polydispersity differ between the two systems in the GPC broad unknown sample measurement results? - WKB87127
Article number: 87127
SYMPTOMS
- GPC measurement shows different Mn, Mw, and polydispersity between the two systems
ENVIRONMENT
- GPC measurement
- 2695 Separations Module
- 2414 Refractive Index Detector
CAUSE
The configuration of both instruments is 2695/2414.
One-minute peak width may be narrower on one instrument, so the polydispersity become smaller proportionately.
FIX or WORKAROUND
- Compare the Narrow Standard sample between the two systems and confirm the difference.
- Ensure that the Sensitivity, Sampling Rate, Time Constant, and Syringe Draw Rate between the two systems are the same.
- Ensure that the lengths and materials of the pipes from 2695 to the column and from the column to the detector are the same.
- Replace the guard column and this column.
- Confirm that the compression check passes.
- Regarding sample preparation, determine if there are any differences in dissolve time and dilution method caused by analysts.
- Confirm the voids between the tubes.
- Ensure that the same Integration is used.
ADDITIONAL INFORMATION
id87127, 2414, 2414B, 2690, 2690D, 2690DUPGD, 2690UP, 2695, 2695D, 2695DE, 2695DEB, 2695DUP, 2695E, 2695EB, 2695INERT, 2695UP, A-10RI, A-10SSM, ALLCOLCLR, ALLCOLHTR, ALLCOLHTRB, EMPGPC, GPCV2K