standard peak in blank

[poli275]

Do you mean the peak appear, say, a blank injection that was followed by 10 previous std or spl injections?

When you say the peak is now showing, do you mean the peak is too small to be integrated, or disappeared at all? Can we have some screenshots for these?

[aslii007]

yes, sometimes i didn't see peak then continued the analysis. but other time i cleaned my systems with same procedure, peak came again. maybe active collects in instrument or in column when i perform sequential analysis. i think, i must clean my system more strong solvents. for example; yesterday, i cleaned my system and column with IPA and peak didi't come.

[poli275]

In that case you found your solution. Please report back if you found that the problem still exist