Estrogenic compounds determination in water samples by dispersive liquid-liquid microextraction and micellar electrokinetic chromatography coupled to mass spectrometry.
In this work, a group of 12 estrogenic compounds, i.e., four natural sexual hormones (estrone, 17β-estradiol, 17α-estradiol and estriol), an exoestrogen (17α-ethynylestradiol), a synthetic stilbene (dienestrol), a mycotoxin (zearalenone) and some of their major metabolites (2-methoxyestradiol, α-zearalanol, β-zearalanol, α-zearalenol and β-zearalenol) have been separated and determined by micellar electrokinetic chromatography (MEKC) coupled to electrospray ion trap mass spectrometry. For this purpose, a background electrolyte containing an aqueous solution of 45 mM of perfluorooctanoic acid (PFOA) adjusted to pH 9.0 with an ammonia solution, as MS friendly surfactant, and methanol (10% (v/v)), as organic modifier, was used. To further increase the sensitivity, normal stacking mode was applied by injecting the sample dissolved in an aqueous solution of 11.5mM of ammonium PFO (APFO) at pH 9.0 containing 10% (v/v) of methanol for 25s. Dispersive liquid-liquid microextraction, using 110 μL of chloroform and 500 μL of acetonitrile as extraction and dispersion solvents, respectively, was employed to extract and preconcentrate the target analytes from different types of environmental water samples (mineral, run-off and wastewater) containing 30% (w/v) NaCl and adjusted to pH 3.0 with 1M HCl. The limits of detection achieved were in the range 0.04-1.10 μg/L. The whole method was validated in terms of linearity, precision, recovery and matrix effect for each type of water, showing determination coefficients higher than 0.992 for matrix-matched calibration and absolute recoveries in the range 43-91%.
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez s/n(o), 38206 La Laguna, Tenerife, Spain; Institute of Chemical Methodologies, Italian National Research Council - C.N.R., Area della Ricerca di Roma I, Via Salaria Km 29,300, 00015 Monterotondo, Rome, Italy.
Giovanni
G
D'Orazio
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez s/n(o), 38206 La Laguna, Tenerife, Spain.
María
M
Asensio-Ramos
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez s/n(o), 38206 La Laguna, Tenerife, Spain.
Javier
J
Hernández-Borges
Institute of Chemical Methodologies, Italian National Research Council - C.N.R., Area della Ricerca di Roma I, Via Salaria Km 29,300, 00015 Monterotondo, Rome, Italy.
Salvatore
S
Fanali
Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez s/n(o), 38206 La Laguna, Tenerife, Spain. Electronic address: mrguez@ull.edu.es.
Miguel Ángel
MÁ
Rodríguez-Delgado
D002210:Caprylates; D020374:Chromatography, Micellar Electrokinetic Capillary; D004967:Estrogens / Q000032:analysis*; D005466:Fluorocarbons; D005618:Fresh Water / Q000737:chemistry; D012739:Gonadal Steroid Hormones / Q000032:analysis*; D059627:Liquid Phase Microextraction; D013058:Mass Spectrometry; D008900:Mineral Waters / Q000032:analysis; D013501:Surface-Active Agents; D062065:Wastewater / Q000737:chemistry
D002210:Caprylates; D004967:Estrogens; D005466:Fluorocarbons; D012739:Gonadal Steroid Hormones; D008900:Mineral Waters; D013501:Surface-Active Agents; D062065:Wastewater; C023036:perfluorooctanoic acid
Dispersive liquid–liquid microextraction; Estrogens; Mass spectrometry; Micellar electrokinetic chromatography; Water samples