HiBack to the Top
I have a problem of negative base line when I run the gradient system
(HPLC).Detection wavelength is fixed at 244 nm. Mobile phase A consists
of an
ammonium acetate buffer (10 mM,PH 4)/ acetonitrile (95/5: v/v). Mobile
phase B
consists of acetonitrile 100%. I am using a flow rate of 1 ml/min and
using
the following gradient profile: 0-50% B (linear) for 45 min.I have the
problem
even when I run the gradient using a blank sample. I would appreciate
if any
member of PharmPK can advise me to solve this problem.
Sayer ALazzam, Pharm D
University Of Iowa, college of pharmacy
email: sayer-al-azzam.at.uiowa.edu
HiBack to the Top
There is always a degree of baseline drift (either positive or
negative) when running a gradient assay with UV detection, simply due
to the changing composition of the mobile phase.
Make sure that your reagents (and water) are of the highest purity
(HPLC grade buffer and gradient grade acetonitrile). Good luck :o)
Ann
Ann Rigby-Jones
Anaesthesia Research Group,
Peninsula Medical School, Universities of Exeter & Plymouth, UK
In phase A and phase B, instead of acetonitrile only, you can useBack to the Top
ammonium acetate 10 mM in acetonitrile. I hope this help you.
Best regards
Stefano Porzio
Pharmacokinetic and Tox. Dept.
Inpharzam Ricerche SA - ZAMBON-GROUP
Taverne - Switzerland
I used to run a gradient like that. The solution is fairly simple--setBack to the Top
your LC detector to autozero at the low point of the gradient, not at the
start of the run as is usually done.
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