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Variation in GPC analysis results
Posted: Fri Dec 03, 2010 9:40 am
by 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.
Re: Variation in GPC analysis results
Posted: Fri Dec 03, 2010 11:48 am
by 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?
Re: Variation in GPC analysis results
Posted: Fri Dec 03, 2010 3:59 pm
by 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?
Re: Variation in GPC analysis results
Posted: Fri Dec 03, 2010 4:46 pm
by 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.
Re: Variation in GPC analysis results
Posted: Fri Dec 03, 2010 5:22 pm
by aarvee2554
Kindly let me know how do I post the chromatograms. I'll do it on Monday.
Re: Variation in GPC analysis results
Posted: Fri Dec 03, 2010 5:31 pm
by tom jupille
Kindly let me know how do I post the chromatograms. I'll do it on Monday.
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