Development of a HPLC-MS/MS confirmatory method for the simultaneous determination of amphenicols in baby formulas using molecularly imprinted polymers

Abstract

Chloramphenicol (CAP) is a broad-spectrum bacteriostatic antibiotic commonly used in veterinary medicine. However, toxic effects in humans such as Grey syndrome, bone marrow suppression, and fatal aplastic anaemia have been described. As a consequence, the use of CAP in foodstuffs has been banned within the European Union since 1994 and no maximum residue limit (MRL) has been established in animal-derived foods. On the other hand, thiamphenicol (TAP) and florfenicol (FLP) are allowed but different MRLs have been set in foodstuffs of animal origin. In this work, precipitation polymerisation has been used and different MIP sorbents were tested and optimized for the solid-phase extraction (MISPE) of a group of three, structurally related amphenicols in milk powder. Recoveries were calculated using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) working in negative mode. The proposed confirmatory method was validated according to the Commission Decision 2002/657/EC, resulting in CCα ranging from 0.06 to 10.5 ng mL⁻¹ and reaching the required working levels. The applicability of these polymers for the extraction of amphenicols in spiked samples of baby formulas has been tested.