- Acknowledgements: This work has been sponsored by Spanish Ministry of Science, Innovation and Universities (Project Ref.: RTI2018-097043-B-I00) and EU Funds. The authors extend their appreciation to Spanish Ministry of Science, Innovation and Universities for granting the Spanish Network of Excellence in Sample preparation (RED2018-102522-T). This article is based upon work from the Sample Preparation Task Force and Network, supported by the Division of Analytical Chemistry of the European Chemical Society. M.M.A.M. is grateful for a predoctoral grant from The Ministry of Science, Innovation and Universities (FPU17/03810).
- Authors: M. Mar Aparicio-Muriana, T. Jirková, F.J. Lara, A.M. García-Campaña.
- Reference: Microchemical Journal 169 (2021) 106595
Capillary liquid chromatography (CLC) with UV-diode array detection has been proposed for the first time to determine fipronil and two metabolites, fipronil-sulfide and fipronil-sulfone in hen egg samples. Under optimum conditions, analytes eluted in less than 12 min. Despite the complexity of egg samples, a simple and fast sample preparation method based on salting-out assisted liquid–liquid extraction (SALLE) was developed using acetonitrile as extraction solvent and ammonium sulfate as salting out reagent. To obtain satisfactory extraction efficiencies for the target compounds, several parameters affecting the procedure were optimized, including the nature and amount of the extraction solvent and the type and amount of salting-out reagent, among others. Validation parameters of the proposed SALLE-CLC-UV method yielded satisfactory results with repeatability and intermediate precision, expressed as relative standard deviation (RSD), below 9% and 11%, respectively and recoveries above 80%. Good linearity was obtained (R2 > 0.990) with limits of detection (LOD) below 5 μg·kg−1. The advantages of a miniaturized technique such as CLC in terms of reduced sample and solvent consumption, combined with simplicity of the SALLE procedure, make this method an attractive green alternative to traditional LC for the monitoring of these residues in egg samples.
