nanoACQUITY problem

hanhgr

<p>hello.</p><p></p><p>Our nanoACQUITY system has some problem.</p><p></p><p>I analyze standard enolase peptide by 60min gradient from 1% solvent B (0.1 % formic acid in ACN) to 60% solvent B (solvent A : 0.1% formic acid in water)</p><p>In normal condition peptide peaks are separate from 25 min to 60 min. But now all peptide peaks are detect on 12 min.</p><p>I think some solvent b come into column when gradient started.</p><p>I checked method but initial condition setting is fine and pump is passed the dynamic leak test and static decay test.</p><p>Anybody can help me please?</p>

KWB

Hello,

If you are not doing this already, try making a complete run of the method at least once before making your 'real' injection.  One group I was in contact with had a similar problem and came to believe that the system 'healed' itself after several runs. I think the more likely explanation is that the both the trap column and analytcal column, as well as the associated tubing, are left in the correct state of equilibration for the separation to work correctly.

Another reason for losing retention could be that the column has become contaminated with something which decreases its active surface area, effectively making it a shorter column. The only way to test this possibility is to replace it.

Ken Blakeslee

hanhgr

Hi

Thanks for your recommend. But I found the reason.

I check pump B flow profile. As I thought in 2D with dilution or 2D online mode some solvent B come into column when gradient started randomly.

I think its software problem.

Hangyeore Lee