Determination of macrolide and lincosamide antibiotics by pressurised liquid extraction and liquid chromatography-tandem mass spectrometry in meat and milk

A total of 155 samples, including meat and milk, were analyzed using a method developed for determining five macrolide antibiotics: tilmicosin (TILM), tylosin (TS), spiramycin (SPM), erythromycin (ERY), and tulathromycin (TULA) and two lincosamide antibiotics: pirlimycin (PIRL) and lincomycin (LM). The method was performed by pressurised liquid extraction (PLE) coupled to LC–MS/MS using electrospray ionization in positive ion mode. 2.5 mL of milk or 2.5 g of meat were dispersed in ethylenediaminetetraacetic acid sodium salt 2-hydrate (EDTA) and sea sand. The PLE conditions as: solvent, temperature, pressure, static time, and cell size were optimized. The following analytical parameters were validated according to the guidelines laid down by European Commission Decision 2002/657/EC linearity, specificity, decision limit (CCα), detection capability (CCβ), repeatability, reproducibility, recovery and ruggedness. The frequency of analyzed antibiotics in milk and meat was 48 and 15%, respectively. Four of positives samples (two of meat and two of milk) were higher than the maximum residues levels (MRLs) established by European Union legislation. The found levels were lower than 78.3 μg/kg in milk and 156 μg/kg in meat. Calculation of the estimated daily intakes (EDIs) from these data showed that contribution of meat and milk to dietary intakes were lower than acceptable daily intakes (ADIs) proposed by JECFA.