Comparison of three solid-phase extraction processes in quantification of ciprofloxacin and enrofloxacin in pork meat

Due to strong implications for food safety, control of fluoroquinolones residues in swine meat should be undertaken to verify compliance of the contamination levels with the maximum residue limits recently updated by Commission Regulation (EU) No. 37/2010 of 22 December 2009. Solid-phase extraction is widely used in antibiotic analysis in food of animal origin. In this study, the results of a comparative study using different types of solid-phase extraction columns, HLB, MCX, and MAX, for ciprofloxacin and enrofloxacin analysis, in pork meat, are presented. In addition, diverse sample treatments for defatting, precipitate proteins, eliminate cations, and increase the ionic strength, were used to obtain the most suitable method of analysis. Only the MCX's use followed by liquid chromatography with fluorescence detection resulted in chromatograms that allow the quantification at maximum residue limits. The validation method, in terms of CCα and CCβ, recovery and precision determination, was according to the EU Decision 2002/657/EC. This procedure was used in the analysis of 50 samples of pork meat of Portuguese origin. Only two samples presented residues of enrofloxacin at 30 and 42 μg/kg, values under the legal maximum residue limit.