The U.S. Department of Agriculture’s Food Safety and Inspection Service (USDA’s FSIS) has recently updated the “Screening and Confirmation of Animal Drug Residues by UHPLC-MS-MS" portion of its Chemistry Laboratory Guidebook. The most updated version, CLG-MRM3.03, took effect on June 1, 2022 and replaces version CLG-MRM3.02.

The Chemistry Laboratory Guidebook contains test methods used by FSIS Field Service Laboratories to support FSIS regulatory activities. “Screening and Confirmation of Animal Drug Residues by UHPLC-MS-MS” describes a multi-residue method that is used by FSIS to test for animal drug residues in FSIS-regulated products. The document describes the method’s applicability, equipment, reagents and solutions, standards, sample receipt and preparation, analytical procedure, decision criteria and calculations, safety information and precautions, and quality assurance plan.