I'm using 1 ml of Tetra Butyl ammonium hydroxide (20%) in my mobile phase(1 lit) to get good resolution. after 1 hr equilibration, if i run the Standard, the RT are found to be changing, indicating column should get stabilized with MP. After the Stabilization of column with mobile phase I'm getting good RT with out change but up on continues run the chromatogram getting a lot of noise even I'm unable to find the PEAKS.
Can any one suggest solution for this problem?
What types of compounds are you are separating.? If possible use simple to simple mobile phase for separation. Main reson of shifting is unstability of mobile phase.
Change of RT indicates that composition of mobile phase changed(pH changed) or your mobile phase affecting on your column after a period of time.
Are you using TBOH as the ion-pair reagent to make you analyte get good peak shape? Does the analyte has negative charge? This reagent is bad for column and should be used at the low concentration (20 mM ). What is your detector (MS?)? I would lower the concentration to the minimum. Need more infor about your analyte.
We found RT shifting in Dimenhydrinate , Mobile phase is 0.1% Triethyl amine adjust pH2.5 with OPA and ACN Colmn Inertsil ODs3 250*4.6mm, 5µ
I know your question is one year old, but here are links to a few HPLC articles which may aid others to solve similar problems.
- "Common Causes of Baseline Noise in HPLC, UHPLC."
- "HPLC Retention Time Drift, Change, Variability or Poor Reproducibility. Common Reasons for it."
- "Modern HPLC Method Development Tips (PART II):"
http://hplctips.blogspot.com/2014/09/common-causes-of-baseline-noise.html
http://hplctips.blogspot.com/2015/11/hplc-retention-time-drift-change.html
http://hplctips.blogspot.com/2016/08/modern-hplc-method-development-tips.html
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