Estrogenic compounds determination in water samples by dispersive liquid–liquid microextraction and micellar electrokinetic chromatography coupled to mass spectrometry

• Published in: Journal of Chromatography A Vol. 1344; pp. 109 - 121
• Main Authors: D’Orazio, Giovanni, Asensio-Ramos, María, Hernández-Borges, Javier, Fanali, Salvatore, Rodríguez-Delgado, Miguel Ángel
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 30-05-2014; Elsevier
• Subjects: Adjustment; Analysis methods; Analytical chemistry; Applied sciences; Biological and medical sciences; Caprylates; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography; Chromatography, Micellar Electrokinetic Capillary; Dispersive liquid–liquid microextraction; Electrokinetics; Estrogens; Estrogens - analysis; Exact sciences and technology; Fluorocarbons; Food industries; Fresh Water - chemistry; Fundamental and applied biological sciences. Psychology; Gonadal Steroid Hormones - analysis; Liquid Phase Microextraction; Mass Spectrometry; Methyl alcohol; Micellar electrokinetic chromatography; Mineral Waters - analysis; Natural water pollution; Non alcoholic beverage industries and mineral waters; Other chromatographic methods; Other wastewaters; Pollution; Recovery; Surface-Active Agents; Waste water; Waste Water - chemistry; Wastewaters; Water samples; Water treatment and pollution; Micellar electrokinetic chromatography; Mass spectrometry; Estrogens; Dispersive liquid–liquid microextraction; Water samples; Trace analysis; Steroid; Validation; Mimetic hormone; Tandem mass spectrometry; Natural mineral water; Chemical analysis; Coupled method; Micellar electrokinetic capillary chromatography; Estrogen; Endocrine disruptor; Runoff water; Electrospray; Waste water; Chemical enrichment; Dispersive liquid liquid microextraction; Sample preparation; Dispersive liquid-liquid microextraction; Non steroid compound; Quantitative analysis
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2014.04.005

•A NSM–MEKC–MS approach using APFO has been developed for the separation of 12 estrogens.•All parameters were carefully optimized, obtaining the separation in less than 11min.•A DLLME procedure was optimized for the extraction of the analytes from water samples.•The DLLME–MEKC–MS method was validated by recovery and calibration studies.•The matrix effect was statistically evaluated obtaining evident positive results.
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 45mM 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 110μL of chloroform and 500μL 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 0.04–1.10μg/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%.