1
$\begingroup$

I used to analyse my compounds on LC-MSdevice with 95% water/5% acn +0,1 formic acid. My column is hypersilgold (C18). When I did my acquisition, I obtain this chromatogram sometimes, and it doesn't depend of my sample, because when I inject again the same sample, it's OK.

Generally, when this problem happens, it disappears after 5-10 injection in a row.

spectrum

Improve this question
$\endgroup$
4
  • $\begingroup$ Can you give us any information about the origin or the nature of "your compounds". Is it a biological extract ? $\endgroup$
    – Maurice
    Commented Feb 13 at 14:45
  • $\begingroup$ It's for non-targeted screening, m/z beetween 50 and 700 m/z. Indeed, it was biological extract. $\endgroup$
    – ChemistryTryHarder
    Commented Feb 13 at 14:50
  • 1
    $\begingroup$ Give information about your compound. Do you use a gradient? When it disappears after multiple injections, the problem can be related to impurities that are included in the mobile phase and that accumulate during ideal state. During gradient run, these impurities may be mobilized.Try, if the background will gradually disappear with continues blanks without any sample injections. $\endgroup$
    – raptorlane
    Commented Feb 13 at 16:08
  • $\begingroup$ I use gradient. Actually, this background disappears after few injections no matter what the matrix is. So, the result is the same if i use blank or sample, after few injections the background will gradually disappear. $\endgroup$
    – ChemistryTryHarder
    Commented Feb 13 at 18:10

0

Reset to default

Browse other questions tagged or ask your own question.