Dear Sir:

Please forward this message to Mr. John V. Hinshaw.
Thanks very much!

Dear Mr. Hinshaw:

It gives me great pleasure to read your paper on "Nosy
problem", published in LCGC,18(2):2000. It is a very
good paper.

I have the same problem, would you please suggest me
further about my case?

I link my HPLC system(Shimadzu, CR501 data integrator)
to LS30 Luminescen spectrometer(Perkin Elmer). I can
not get a stable baseline( the attenuation in the
CR501 integrator:3, and 2048, or less in LS30). There
is much noise. and the slope set by S.TEST in CR501 is
more than 2000. I have to set the slope manuuly to
less than 1500 if I need to detect small amount of
sphingolipids, some metabolites of lipids in bilogical
samples, by LS30 fluorecence spectrometer.

Last September, we detected the S/N ratio for LS30
detector, the S/N was 47.5. Is it OK?

In addition, I can listen to some small noise similiar
to the electric current sound in the LS30. Whether is
the Xenon lamp OK?

I look forward to hearing from you.

I greatly appreciate your kind help!


Quanren He, MD
department of physilogy and pharmacology
the college of Veterinary Medicine
the University of Georgia
Athens, GA 30602
phone: (706)542-2789
Fax:(706)542-3015

You will need to find out from PerkinElmer what the expected noise and drift levels are for your luminescence detector at the settngs and elution conditions you use -- I am forwarding your message to their LC department. They can also answer your question about the noise associated with the Xenon lamp.

Once your detector is in good working order you can determine if the noise and drift levels it produces are low enough to permit you to detect the sphingolipids in which you are interested.

--- John Hinshaw