The present work describes a successful application of microextraction packed sorbent and liquid chromatography with diode array detection (MEPS/LC-DAD) for simultaneous determination of the sulfonamides (sulfacetamide, sulfadiazine, sulfathiazole, sulfamethazine, sulfamethoxypiridazine and sulfamethoxazole) in egg samples. The MEPS variables (pH of the sample, draw-eject cycles, ionic strength, and desorption procedure) were optimized, in order to improve the sensitivity of the proposed method. The method was shown to be linear at concentrations ranging from 30 ng g-1 (limit of quantification, LOQ) to 300 ng g-1. This LOQ value is lower than those established as the maximum residue limit (MRL) for egg samples (100 µg kg-1). The accuracy values were adequate for all analytes (> 94%), as well as the inter-day precision data, with coefficient of variation lower than 10%. On the basis of analytical validation, the MEPS/LC methodology has been shown to be a promising alternative for analysis of sulfonamides in egg samples.
MEPS; sulfonamides; liquid chromatography; egg
