Determination of organophosphate flame retardants in soil and fish using ultrasound‐assisted extraction, solid‐phase clean‐up, and liquid chromatography with tandem mass spectrometry

A solid–liquid extraction method in combination with high‐performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean‐up by solid‐phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50–121% for soil and 47–123% for biota, both with high precision (RSDs <12% in soil and <23% in biota). The method limits of detection ranged from 0.06 to 0.20 ng/g dry weight and between 0.02 and 0.30 ng/g wet weight for soil and biota samples, respectively. However, samples with a high lipid content produce several problems as solid‐phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively.This work has been supported by the Spanish MINECO and the ERDF through the project CGL2015‐64454‐C2‐1‐R (ECO2risk‐dds) and the University of Valencia through the project UV‐INV‐AE15‐348995. M. Lorenzo was supported by the Foundation “Tatiana Pérez de Guzmán el Bueno” (predoctoral grant 2014).Peer reviewe