By David B. on Monday, November 1, 1999 - 11:32 am:
I am running in series a PDA and an ELSD (Light Scattering Detector). Each were calibrated with the same injected calibrators (range 100-1000 ppm). Fits are very good and as expected: linear fit for PDA, quadratic for ELSD.
However, when running an unknown, for some odd reason, the ELSD results are 10-15% higher than the PDA's. The mobile phase is volatile.
Any help/inputs on that problem will be greatly appreciated.
By Anonymous on Tuesday, November 2, 1999 - 12:05 am:
Easiest explanation is a co-eluting interference that has no chromophore.
By hinsbarlab on Tuesday, November 2, 1999 - 09:20 am:
Is this a polymer? If so, what kind? Are the calibrators the same type and lot number as the sample? If you re-inject a standard, does the ELSD result come out 10-15% higher or just with samples?
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