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ELSD vs PAD

Posted: Tue Sep 06, 2005 4:29 pm
by Sallybeetle
I will be developing HPLC methods for Neomycin, Gentamicin, Spectinomycin, and Tylosin antibiotics. From my literature searches, I gather that ELSD (evaporative light scattering detection) and PAD (pulsed amperometric detection) are the two detection methods of choice for these compounds.

Each detector appears to have many pros and cons for use in the raw material and finished product analysis of these antibiotics. For example, I have been told that ELSD is quadratic and may not be linear or have very good precision; but, PAD may be a maintenance nightmare with the basic mobile phase and post-column basic solution.

Does anyone have any advice on which detector and brand is best for these analyses?

In advance, thank you very much for for any advice I receive from this post.

Posted: Wed Sep 07, 2005 6:57 pm
by sdnico
Sallybeetle,
I have little experience with a PAD, but I am fairly familiar with the ELSD.
I have had little to no problems with precision using a SEDEX 55 by SEDERE.
The system has been fairly easy to maintain as well. A simple cleaning by pumping the appropriate solvents through the nebulization chamber is pretty much all it takes.
Linearity can be an issue with these detectors. Therefore, all of my testing has been a comparrison of sample to a standard curve using second order coefficients.

Not sure if this is any help to you. Hope you find the answers you need.

sdnico

PAD vs ELSD

Posted: Tue Sep 13, 2005 8:13 pm
by Sallybeetle
Thank you very much for your input. This is very useful information.

If anyone is familiar with PAD, I would very much like to hear of your experiences, also.