Optimized Extraction and Cleanup Protocols for LC-MS/MS Multi-Residue Determination of Veterinary Drugs in Edible Muscle Tissues
In order to ensure public health and safety, a reliable screening analysis is necessary to determine veterinary drug residue levels in meat and other edible tissue samples. The compounds of interest range from highly polar water-soluble compounds to very non-polar, fat-soluble compounds. There exist very effective extraction and cleanup procedures for individual compounds or compound classes, but these methods are not well suited for a multi-class, multi-residue screening analysis.
Solvent extraction (with excess acetonitrile or methanol) can be effective for many veterinary drug residues in milk, but highly water soluble drugs such as salbutamol are not well recovered using this approach.
Aqueous buffer extraction can also be effective for many compounds, but fat-soluble compounds, such as dexamethasone, are not well recovered using this approach.
Traditional solid-phase extraction (SPE) enrichment and cleanup (retention/wash/elution) has limited utility for multi-residue analysis. Because the range of acidity/polarity/solubility among the compounds is so broad, dispersive, or pass-through SPE is preferred for multi-residue methods.