Fast ultrasound-assisted extraction combined with LC-MS/MS of perfluorinated compounds in manure

A fast analytical method for the determination of perfluorinated compounds in poultry manure by LC-MS/MS was developed. The extraction was carried out by ultrasound-assisted extraction of 1 g of sample, during 2 × 15 min using low volume (5.5 mL) of a mixture of methanol and acetonitrile. An efficient extraction of perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and perfluoroalkyl sulfonamides from poultry manure was obtained with recoveries higher than 81%. The cleanup of extracts was carried out by dispersive SPE. The validation of the proposed method showed the suitability of this procedure to determine perfluorinated compounds in poultry manure with detection limits in the range of 0.44-2.12 ng/g, depending on the target compound. In comparison with previously published methods, the miniaturization of the sample preparation method with ultrasound-assisted extraction together with the use of a core-shell column permit a lower consumption of organic solvents and a fast analysis of perfluorinated compounds. Manure samples obtained from Spanish commercial farms were analyzed and low perfluorinated compounds levels were found, which may be originated by dietary or environmental exposure. The highest concentrations measured corresponded to the perfluoroalkyl sulfonates, which varied from 8.2 to 35.9 ng/g.