what to do to reduce peak tailing?

[moonchips]

I developed a short assay for a free base drug. And now they have it in a salt form. I used the same method, and I got very bad peak tailing.

original settings are:
YMC pro RP C18 100*4.6*5 um
A: water with 0.05% TFA
B: methanol
Column Temp: 25 C
flow: 1 ml/min
a gradient analysis.
RT~5.5 min

Please give me suggestion if you have any about this issue
Thanks

[danko]

Add 0.05% TFA to the B eluent.

Best Regards

[grzesiek]

if i may i would suggest posting chromatograms for all of us

[SiliCycle]

My suggestion is SiliaChrom SB C18 or SiliaChrom XDB C18 (2). Those columns gave better peak shape for basic drugs (HPLC column designed for basic compounds). I tested in my lab against Zorbax SB C18 and Luna C18(2) and got no tailing for amytriptyline. New HPLC columns on the market which have been released at HPLC 2009 conference in Germany. I have also tested the SiliaChrom SB C18 at pH=1.0, so no degradation after a week no stop.
If you need more infos let me know.

[moonchips]

if possible, could anyone tell me possible reasons for peak tailings?

[SiliCycle]

if possible, could anyone tell me possible reasons for peak tailings?

Too much silianol activity on the silica-based reversed phase HPLC column. And/or some metal effects causes Lewis acid (metal complex with basic analyte). There are others reasons but these two are more important.

[HW Mueller]

If you have a low number of SiO-/SiOH you can still get horrendous tailing if the pH and/or ionic strength is wrong.