Determination of perfluorinated compounds, bisphenol A, anionic surfactants and personal care products in digested sludge, compost and soil by liquid-chromatography-tandem mass spectrometry

Abstract

A method for the determination of 23 emerging concern pollutants in digested sludge, compost and soil has been developed. Target pollutants include six perfluorinated compounds (5 perfluorocarboxylic acids and perfluorooctanesulfonic acid), the plasticizer bisphenol A, four anionic surfactants (sodium alkylsulfates), four preservatives (parabens), two antimicrobial agents (triclosan and triclocarban) and six UV-filters (benzophenones). Sample treatment was based on ultrasound-assisted extraction with 3 mL of methanol:acetic acid (95:5, v/v) and clean-up by dispersive solid-phase extraction (d-SPE) with C18. Analytical determination was carried out by liquid chromatography-tandem mass spectrometry. Extraction solvent, sonication time, number of extraction cycles and type and amount of d-SPE sorbent were optimized. Due to the physical-chemical properties of target compounds, and the high number of sample treatment variables involved, a Box-Behnken design was applied to method optimization. The method was validated by means of spiked samples. Method detection limits were in the range from 0.01 to 6.2 ng g−1 dry matter. Accuracy and precision were evaluated at three spike levels in each type of sample matrix. Accuracy, expressed as relative recovery, was in the range from 70% to 120% for most of the compounds and spike levels. Precision, expressed as relative standard deviation, was equal or below 21%. To the best of our knowledge, the proposed method constitute the first analytical method for multiclass determination of emerging pollutants in digested sludge, compost and soils.