AOAC SPIFAN Stakeholder Program Meeting Book (September 10, 2020)

Analytical Challenges and Techniques • Analytical challenges caused mainly by properties of chlorate & perchlorate: • Small, highly polar anions • Not possible to include in typical pesticide multiresidue methods • Low m/z MS ions for quantitation and identification • Ubiquitous in the environment • Potential for contamination during sampling and analysis • Difficulty finding suitable matrix blanks for validation of low LOQs in certain matrices • Analytical techniques • Liquid chromatography – tandem mass spectrometry ( LC-MS/MS ) with HILIC, porous graphitic carbon or anion exchange columns, such as in the QuPPe methodology • Ion chromatography – tandem mass spectrometry ( IC-MS/MS )

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Quick Polar Pesticides (QuPPe) Method • Extraction with acidified methanol containing isotopically labeled ISTDs (water added to dry matrices) • Possibility to analyze other anionic pesticides together with chlorate & perchlorate • Different LC-MS/MS methods:

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