Organophosphorus pesticide peaks separation

[badrul]

Good day everybody. Can anyone help me solve this problem in separating the peaks for organophosphorus pesticides.

Monocrotophos, quinalphos, pirimiphos-methyl, diazinon, dimethoate, phenthoate, malathion, fenitrothion, dichlorvos, prothiophos, parathion-methyl, trichlorfon, methamidophos, fenthion, profenofos, chlorpyrifos, sulfotep, acephate, azinphos-ethyl, triazophos.

I've tried various combinations of oven temperature programming, inlet temperature, detector temperature, and so on but to no success in separating all 20 peaks. So anybody have any idea on the best optimize GC parameters to separate these peaks? I'm still searching for the best optimization (columns, oven temperature programming [primary, secondary], inlet temperature, detector temperature) as I write this post ...

Really looking forward and appreciate any comments and suggestions from all of you. Thank you.

By the way, I'm using GC x GC (LECO/Agilent 7890) with FPD detector. Primary column = Rtx-5, secondary column = Rtx-17. Currently I just using the 1D mode.

[Schmitty]

We do a lot of those pesticides, but we run dual injections on both an rtx-5 and 1301 column. I can't give away the farm, but I'm sure a column manufacturer would be happy to help you with additional information.

[astroguille]

Hi!

Did you try with pulsed injection? The peaks will show more narrow, and this can improve the resolution.