I can tell you that determining transitions (SRMs) for GC-MS/MS can be quite challenging with so many precursor ions to evaluate. I spent a considerable amount of time optimizing transitions for our GC Multiresidue Pesticide Kit which has 203 compounds. That is a lot of transitions to evaluate!
I also tested my chromatographic method for analyte to analyte interferences by comparing ion ratios. The ion ratio of qualifying Q3 ion to quantification Q3 ion for each compound tested in small subsets was compared to the ion ratio determined in the presence of all 203 compounds. When the two ratios fell outside of plus/minus thirty percent, this indicated analyte to analyte interference and alternative transitions were used.
Transitions for all compounds and notes about analyte to analyte interferences and shared transitions can be found in this downloadable spreadsheet. The data was collected and optimized on our Thermo Scientific™ TSQ™ 8000 Triple Quadrupole GC-MS System.
The spreadsheet provides the method conditions (last tab), retentions times and three SRMs per compound. CAS numbers and isomers information is also included.
I hope that this helps accelerate your method development!
Shopping list for this method:
- GC Multiresidue Pesticide Kit
- Rxi-5ms (cat# 13423)
- Restek Premium liners (Single Taper with wool for Thermo TRACE™ 1310)
- Internal Standards and/or Surrogates
Tags: Method Development, pesticide residues, pesticides, Standards
Hi.
This is a great post. What about LC MS/MS TQ. Have you or are you planning to do any transitions work for pesticides? That would be very valuable as well, especially for an agilent system.
I have posted LC-MS/MS transitions for our LC Multiresdue standard
The spreadsheet can be found here…click “downloadable XLS file”.
thank you
Julie