By user on Tuesday, July 20, 2004 - 04:30 am:

Anyone encounter poor baseline noise from Waters 2420 ELSD detector running in THF for GPC work?

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By AA on Tuesday, July 20, 2004 - 04:54 am:

Define poor noise.
What are your ELSD conditions?

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By user on Tuesday, July 20, 2004 - 05:43 am:

Column=35deg
Nebulizer flow=45psi
Nebulizer temp=60% (36deg)
Drift temp= 50deg
LC flowrate=1ml/min

I can see the small pulsation in the baseline which is worse when I zoom in.

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By Hugh on Tuesday, July 20, 2004 - 07:52 am:

Are you running stabilized THF? You may be seeing the stabilizer.

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By AA on Tuesday, July 20, 2004 - 04:58 pm:

The original question still stands, what is the noise? How many mV or LSU are you talking about?

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By user on Wednesday, July 21, 2004 - 02:39 pm:

I obtain my LSU signal for the peak at 1400. Noise is still obvious at this signal.

Also run this detector in series with UV detector and the noise problem is not observed at all.
Any suspicion that the drift tube not clean or stuck with those THF solvent residue?

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By user on Wednesday, July 21, 2004 - 02:42 pm:

I guess the noise that I observed might come from the dirty drift tube. The noise is around 3LSU, which is more obvious sometimes at the first half of the injection run, while other times at the nearing to the end of the injection run. This noise gets more obvious as the number of my injections increase.