Integrated procedure for determination of endocrine-disrupting activity in surface waters and sediments by use of the biological technique recombinant yeast assay and chemical analysis by LC-ESI-MS

An integrated procedure using mass spectrometry and molecular biology for determination of estrogenicity in natural waters and sediments is reported. Solid-phase extraction (SPE) and pressurized-liquid extraction (PLE), respectively, were used for isolation of endocrine-disrupting compounds (EDC) from surface waters and sediments, followed by liquid chromatography-mass spectrometry using an electrospray interface (LC-ESI-MS). Twenty seven EDC were determined: non-ionic surfactants (nonylphenol ethoxylate), alkylphenols (e.g. nonylphenol and octylphenol), bisphenol A, phthalates, and natural and synthetic steroid sex hormones. Limits of detection varied from 0.02 to 0.22 mug L-1 and from 1 to 10 mug kg(-1) in water and sediments, respectively. Recoveries ranged from 65 to 125% and 73 to 97% for waters and sediments, respectively. In addition to LC-ESI-MS determination, extracts obtained by SPE and PLE were analyzed by the recombinant yeast assay (RYA) to assess total estrogenic activity. This bioassay detects natural estrogens and xenoestrogens, producing a quantitative measurement of EDC irrespective of the identity of the chemical responsible for the activity. As a novelty, a relative estrogenicity factor was determined for 19 analytes with EC50 values ranging from 10(-10) to 10(-9) mol L-1 for synthetic estrogens, from 10(-7) to 10(-5) mol L-1 for alkylphenol derivatives, and from 10(-5) to 10(-4) mol L-1 for phthalates and benzothiazoles. By use of this integrated chemical-ecotoxicological approach good correlation was usually established between chemical composition and estrogenic effects for surface water and sediment samples from Portugal. Estrogenic activity observed was mainly attributed to the presence of nonylphenolic compounds (with concentrations of NP ranging from 0.1 up to 44 mug L-1 in waters and up to 1172 mug kg(-1) in sediments), and to the sporadic presence of estrogens, detected at ng L-1 levels.