Internal standards for pesticide residues analysis, with GC -MS/MS and optimization approach

Have you checked Cambridge isotopes for isotopically labelled internal standards?

What are the specific problems you are having that you need assistance with? Lots of pesticides (particularly organochlorine and carbamates) can decompose in a hot active site (liner, columns and source body). Have you tried injecting your samples with analyte protectants? Do an internet search for analyte protectants and gulonolactone or sorbitol and you'll find lots of protocols for doing co-injections to enhance and stabilize your pesticide response. The original paper was written by Lehotay, Anastassides et al. (too lazy to look it up).

Agilent has published lots of material on pesticide residues analysis with GCMSMS so you should easily be able to find the transitions and collision energies required for the pesticides you mentioned.

/r/massspectrometry Thread