Potentiality of IMAC as Sample Pretreatment Tool in Food Analysis for Veterinary Drugs
Immobilized metal ion affinity chromatography (IMAC) was evaluated as a sample pretreatment tool for residual veterinary drugs (VDs) in food. A test of six cations for the IMAC efficiency revealed that Cu2+ and Fe3+ were suitable in retaining tetracyclines, quinolones (QLs: fluoroquinolones, acid quinolones), macrolides, β-lactams, and aminoglycosides, but ineffective for sulfonamides and hormones. These results showed the IMAC had great potential for a multiclass multiresidual VDs analysis in a simple and selective way. This methodology was applied on milk analysis for eleven QLs, involving extraction with (1:1) acetonitrile/methanol and IMAC with Fe3+. Averaged recoveries ranged from 68 to 93% and limits of quantitation from 2 to 26 ng mL−1. Ten commercial milk samples were found to be free from the QLs.