Development of thin film SPME sorbents based on deep eutectic solvents and their application for isolation and preconcentration of endocrine-disrupting compounds leaching from diapers to urine

In this study, the thin film solid phase microextraction (TF-SPME) based on a novel sorbent composed of deep eutectic solvent (DES) is proposed. Among several synthesized sorbents the most efficient was DES containing trihexyl(tetradecyl)phosphonium chloride and docosanol mixed with polydimethylsiloxane (PDMS) in a molar ratio 1:3:0.25 to achieve a more stable structure. The proposed sorbent was applied on a fiberglass mesh and used as a TF-SPME sorbent for the determination of fifteen endocrine-disrupting compounds (EDCs): methylparaben (MeP), ethylparaben (EtP), propylparaben (PrP), butylparaben (BuP), benzylparaben (BzP), bisphenol A (BPA), bisphenol S (BPS), bisphenol F (BPF), bisphenol AF (BPAF), bisphenol E (BPE), bisphenol B (BPB), triclosan (TCS), triclocarban (TCC), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) leaching from diapers to synthetic urine. A central composite design methodology was used to optimize extraction from urine and four factors were tested, such as mass of DES/PDMS, extraction time, desorption time, and volume of triethylamine (additive to the desorbing solvent). The developed methodology was characterized by good metrological parameters (limit of detection (LOD): 0.01-1.15 ng mL-1, precision: 2.5-10.3 %). The method was linear in the range of 0.1 ng mL-1 to 100 ng mL-1 with a satisfactory coefficient of determination. After preconcentration by TF-SPME, EDCs were determined by LC-MS/MS. The main EDCs found in diapers were BPA, BPS, MeP, EtP, and PrP.