Determination of Ethopabate Residues in Chicken Muscles, Liver, and Eggs after Aqueous SDS Extraction by Micellar Liquid Chromatography with Fluorescence Detection with Application to Baby Food

Abstract

A simple and sensitive liquid chromatographic method was optimized and validated for the analysis of ethopabate residues in chicken muscles, liver, and eggs. Aqueous sodium dodecyl sulfate (SDS) solution was used for extraction. Analytical separation was performed in less than 8 min using a C18 column (150 × 4.6 mm internal diameter, 5 μm particle size) with fluorescence detection at 271/364 nm. A micellar solution composed of 0.1 M SDS, 10 % 1-propanol, and 0.3 % triethylamine in 0.02 M phosphoric acid adjusted to pH 4 was used as the mobile phase. The method was fully validated in accordance with International Conference on Harmonization guidelines. The micellar method was successfully applied to quantitatively determine ethopabate residues in spiked chicken muscles, liver, and eggs. It was also extended to the determination of ethopabate residues in chicken-based baby food. The recoveries obtained were in the 93.81–115.67 % range. The limit of detection was found to be 1.6 ng/g. High extraction efficiency for ethopabate was obtained without matrix interference and in the subsequent chromatographic determination. No organic solvent was used during the pretreatment step.