Focused ultrasound solid-liquid extraction of perfluorinated compounds from sewage sludge

► FUSLE has been applied to the analysis of PFCs for the first time. ► PFCs stability under FUSLE irradiation has been proved. ► FUSLE optimization: two extraction cycles of 20 s at 65%. ► The FUSLE-UPLC-MS/MS method is simpler and faster than previously reported methods. ► Determination of PFCs in sewage sludge samples from La Rioja.