Linear regression parameters of the calibration curve of fipronil and its three metabolites in all matrix matrices and solvents for 0.005–0.25 mg/kg.

<p>Linear regression parameters of the calibration curve of fipronil and its three metabolites in all matrix matrices and solvents for 0.005–0.25 mg/kg.</p

Residue analysis and persistence evaluation of fipronil and its metabolites in cotton using high-performance liquid chromatography-tandem mass spectrometry - Fig 1

<p>UPLC-MS/MS MRM chromatograms of fipronil and three metabolites of (A) standard (5 mg/kg), (B) cottonseed spiked at 10 mg/kg, (C) total ion chromatogram of the four test compounds in the 0-day (2 h) cotton plant sample.</p

Half-life (T_1/2) and other statistical parameters for fipronil dissipation in the cotton field conditions.

<p>Half-life (T_1/2) and other statistical parameters for fipronil dissipation in the cotton field conditions.</p

UPLC-MS/MS conditions of fipronil and its three metabolites.

<p>UPLC-MS/MS conditions of fipronil and its three metabolites.</p

Simultaneous determination of three pesticides and their metabolites in unprocessed foods using ultraperformance liquid chromatography-tandem mass spectrometry

<p>We have developed a rapid, multi-compound analytical method for measuring residues of the pesticides thiamethoxam and its metabolite, clothianidin; fipronil and its three metabolites, fipronil sulfone, fipronil sulfide, and fipronil desulfinyl; and pyraclostrobin in unprocessed foods (rice, corn, cucumbers, tomatoes, apples, and bananas) by ultra-performance liquid chromatography coupled to tandem mass spectrometry. Acetonitrile was used as the extraction solvent, and an octadecylsilane-dispersive SPE was used to clean up the analytes, which were then separated through a UPLC HSS T3 column connected to a tandem mass spectrometer via an electrospray ionisation source. The linearity of this method for the target analytes was excellent (<i>R</i>² ≥0.990) in the concentration range of 5–1000 μg kg^–1. The average recoveries of the seven compounds at concentrations of 10, 100, and 1000 μg kg^–1 from six spiked matrix samples ranged from 73.6 to 110.6%, all with RSD values of ≤19.7%. The limit of quantification was 10 μg kg^–1. The method validated the effectiveness of the method for routine monitoring the residue of these pesticides and their metabolites in foods.</p