Variation in GPC analysis results

[aarvee2554]

I'm running phenolic resin samples in Perkin Elmer GPC system. The total polymerisation time is 6 hours. I collect samples during every hour and test for the molecular weight distribution. The chromatogram and the SEC data of the first hour sample is almost similar to the final sample, which is not possible. Please through some light into the reasons.

[bhuvfe]

Few thoughts.

Are you sure the system is OK? Do you see something strange in the standards you use?

Did you run also the time-zero sample?

How does the chromatogram look like?

[aarvee2554]

I use polystyrene standards for calibration and calibration results are quite ok. The chromatogram contains a perfect baseline. But one thing is the columns are about 10 years old. Will this lead to this error?

[bhuvfe]

Normally, the columns should be OK if stored correctly.

If you inject the "monomer" how does it compare with the 1-h sample?

Posting one or two chromatograms might shed some light.

[aarvee2554]

Kindly let me know how do I post the chromatograms. I'll do it on Monday.

[tom jupille]

Kindly let me know how do I post the chromatograms. I'll do it on Monday.

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