Determination of fipronil and its metabolites in egg samples by UHPLC coupled with Q-Exactive high resolution mass spectrometry after magnetic solid-phase extraction

A novel, rapid and simple magnetic solid-phase extraction (MSPE) method combined with ultra-high performance liquid chromatography coupled with Q-Exactive high resolution mass spectrometry (UHPLC-Q-Exactive HRMS) was proposed for determination of fipronil and its metabolites in egg samples. In this study, novel polydopamine functionalized magnetic core-shell mesoporous silica nanoparticles (Fe3O4@nSiO(2)@mSiO(2)-PDA) were used as MSPE adsorbent for purification and enrichment of fipronil and its metabolites for the first time. The proposed method showed a good linearity (R-2 >= 0.997), high sensitivity (limit of detection in the range of 0.002-0.004 mu g/kg and limit of quantification in the range of 0.006-0.010 mu g/kg), adequate recovery (80.6-95.3%) and repeatability (intra-day precision in the range of 2.2-6.7% and inter-day precision in the range of 4.4-10.7%). Finally, the developed MSPE-UHPLC-Q-Exactive HRMS method was successfully applied for determination of fipronil and its metabolites in egg samples.

Automated summary

A novel MSPE method combined with UHPLC-Q-Exactive HRMS was proposed for determination of fipronil and its metabolites in egg samples, utilizing Fe3O4@nSiO(2)@mSiO(2)-PDA as the adsorbent. The method showed good linearity, high sensitivity, adequate recovery, and repeatability, and was successfully applied for determination of fipronil and its metabolites in egg samples.