by
Rndirk » Sun Jun 24, 2018 7:03 pm
Hey Alberto,
It would be easier if someone could show you these things hands-on.
Albertospd wrote:
I order the compounds in order of RT and I take for each compound three ions?
Yes. Within a window, the order of compounds does not matter. They are all measured across the window. I believe 2 ions for pesticides is generally accepted.
Albertospd wrote:
in case of molecules that come out at very close times, how can I divide the buying window?
You want to avoid putting a window end/start when a peak elutes. I think this also depends on software - i can image some software can deal with this, but it's not an ideal situation since there is likely a baseline and peak point difference hindering a good quantification. Look at full scan chromatogram and look for spots where no compounds are eluting, for example:
Window 1 start @ 9,00minMethomyl, 10,00 105 71
Hexaflumuron 10,43 141 113
Acephate 11,65 136 94
Window 1 end @12,30minWindow 2 start @12,30minCimoxanil 13,00 111 167
Triflumuron 13,70 139 155
Ortofenil fenolo 14,00 170 169
Ethoprophos 14,50 158 97
Lufenuron 14,65 176 178
Window 2 end @ 15,50minWindow 3 start @ 15,50minOmethoate, 16,47 156 110
........
Do you have knowledge about peak points/dwell times or is this concept new for you? For advice about these settings, we'll need to know how wide the peaks are (+-).