Restricted Access Volatile Supramolecular Solvents for Single-Step Extraction/Cleanup of Benzimidazole Anthelmintic Drugs in Milk Prior to LC-MS/MS.

In this work, a restricted access volatile supramolecular solvent (RAM-VOL-SUPRAS) directly synthesized in milk is proposed for the first time for the simultaneous extraction and cleanup of benzimidazole anthelmintic drugs in milk meant for human consumption. The RAM-VOL-SUPRAS was formed by the self-assembly and coacervation of hexanol in tetrahydrofuran induced by the water content in milk. Benzimidazoles legislated by the European Union were quantitatively extracted (80-110%), and proteins were precipitated by the action of THF and the amphiphile; extraction of carbohydrates was avoided by a size exclusion mechanism, and lipids were removed during hexanol evaporation. The analytical methodology was fully validated according to Commission Decision 2002/657/EC. Method detection limits from 0.03 to 0.14 μg L-1 were well below the maximum residue limits legislated in milk for these drugs, with interday precisions at maximum residue levels below 13%. This novel methodology guarantees a rapid and reliable tool for daily and routine laboratory analyses in the field of food quality control.