The Food and Drug Administration (FDA) Denver Human and Animal Food Laboratory (DENHAFL) requires custom-prepared, multi-component analytical reference standard solutions for use in the regulatory ana... The Food and Drug Administration (FDA) Denver Human and Animal Food Laboratory (DENHAFL) requires custom-prepared, multi-component analytical reference standard solutions for use in the regulatory analysis of veterinary drug residues in aquaculture, dairy, and game-meat products. The standards support initial calibration verification (ICV) and continuing calibration verification (CCV) in screening and confirmatory liquid chromatography–mass spectrometry (LC-MS) methods.