Table of Contents
Advertisement
Product Manual for ProPac
5.1.2.
Peak efficiency and resolution is poor.
1. Try to use different eluents (buffer, pH, concentration etc.); to make sure you are using the optimum conditions for
your separation problem.
2. The column may be overloaded. Dilute the sample and/or inject smaller volumes.
5.1.3.
Peak retention time varies from run-to-run.
1. The column may not be adequately equilibrated or washed.
2. Make sure that the equilibration time is adequate and remains constant after every gradient run. Re-equilibration
should be part of the method.
3. Column washing is usually not necessary between every run, unless your sample is extremely "dirty." If you need to
use a wash, a consistent and adequate method for washing and equilibrating should be part of the method.
5.2.
No Peaks, Small Peaks, Noisy Baseline
5.2.1.
Detection Problem
Make sure that you are using the correct wavelength for your sample/buffer system. Adjust the selected detector range (AU)
according to your injected sample amount. Check your lamp: aged UV lamps tend to give noisier response. Replace the lamp
if necessary.
5.2.2.
Chromatographic Problem
Make sure that your sample can be eluted with the buffers and conditions you are using. Before trying a gradient separation,
try isocratic elution with 100% B (high salt) buffer: the sample should elute at, or near to, t0 (void). If not, try a higher salt
concentration or different pH.
5.2.3.
Pump Problem
A noisy baseline can be caused by an improperly working pump. Be sure the pump is primed. Test the flow rate and also the
pump head pressure fluctuation according to your pump manual.
Document No. 065403-01
®
SCX-20
©2010 DIONEX CORPORATION
Page 16 of 21
September 2010
Advertisement
Table of Contents
