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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

  1. Compare the Narrow Standard sample between the two systems and confirm the difference.
  2. Ensure that the Sensitivity, Sampling Rate, Time Constant, and Syringe Draw Rate between the two systems are the same.
  3. Ensure that the lengths and materials of the pipes from 2695 to the column and from the column to the detector are the same.
  4. Replace the guard column and this column.
  5. Confirm that the compression check passes.
  6. Regarding sample preparation, determine if there are any differences in dissolve time and dilution method caused by analysts.
  7. Confirm the voids between the tubes.
  8. 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

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