Restricted access property supramolecular solvents for combined microextraction of endocrine disruptors in sediment and sample cleanup prior to their quantification by liquid chromatography-tandem mass spectrometry.

ABSTRACT

A supramolecular solvent (SUPRAS) made up of inverted hexagonal aggregates of decanol was here proposed for the simultaneous microextraction of representative estrogenic disruptors (EDs) [viz. estrone (E1), 17ß-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2) and bisphenol A (BPA)] in sediments and sample cleanup. The SUPRAS contains aqueous cavities, the size of which can be tailored by controlling the environment for decanol self-assembly. The method involved the stirring of the sample (0.3g of sediment) with 0.4mL of SUPRAS for 10min, subsequent centrifugation for extract separation from solid matrix components and direct analysis of the extract by liquid chromatography/triple quadrupole mass spectrometry (LC/QQQMS-MS). Driving forces for the microextraction of EDs in the SUPRAS involved both dispersion and hydrogen bond interactions. This mixed-mode mechanism resulted in high extraction efficiencies for EDs (viz. recoveries between 93 and 104%) and that allowed to reach low method detection limits (viz. 0.03, 0.3, 0.28, 0.4 and 0.08ngg(-1) for E1, E2, E3, EE2 and BPA, respectively) without the need for extract evaporation. The size of the aqueous cavities of the SUPRAS selected was no large enough to allow humic acids to efficiently diffuse through them. So the SUPRAS behaved as a restricted access material for these macromolecules thus facilitating sample cleanup. The method was applied to the determination of the targeted EDs in sediments from three rivers in the Southern Spain. The concentrations found ranged between below the MDL and 6.4ngg(-1). The sample treatment here proposed greatly simplifies the procedures currently used for the determination of EDs in sediments using LC/MS-MS.