Liquid chromatography tandem mass spectrometry method using solid-phase extraction and bead-beating-assisted matrix solid-phase dispersion to quantify the fungicide tebuconazole in controlled frog exposure study: analysis of water and animal tissue

This paper presents the development, optimization, and validation of a LC-MS/MS methodology to determine the concentration of the antifungal drug and fungicide tebuconazole in a controlled exposure study of African clawed frogs (Xenopus laevis). The method is validated on animal tank water and on tissue from exposed and non-exposed adult X. laevis. Using solid-phase extraction (SPE), the analytical method allows for quantification of tebuconazole at concentrations as low as 3.89 pg mL^?1 in 10 mL water samples. Using bead-beating-assisted matrix solid-phase dispersion (MSPD), it was possible to quantify tebuconazole down to 0.63 pg mg^?1 wet weight liver using 150 mg tissue. The deuterated analogue of tebuconazole was used as internal standard, and ensured method accuracy in the range 80.6–99.7 % for water and 68.1–109 % for tissue samples. The developed method was successfully applied in a 4-week X. laevis repeated-exposure study, revealing high levels of tebuconazole residues in adipose and liver tissue, and with experimental bioconcentration factors up to 18,244 L kg^?1.