Dispersive liquid–liquid microextraction versus single-drop microextraction for the determination of several endocrine-disrupting phenols from seawaters

• Published in: Talanta (Oxford) Vol. 80; no. 5; pp. 1611 - 1618
• Main Authors: López-Darias, Jessica, Germán-Hernández, Mónica, Pino, Verónica, Afonso, Ana M.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.03.2010; Elsevier
• Subjects: Analytical chemistry; Chemical Fractionation - methods; Chemistry; Chromatographic methods and physical methods associated with chromatography; Chromatography, High Pressure Liquid - methods; Dispersive liquid–liquid microextraction; Endocrine Disruptors - analysis; Endocrine-disrupting phenols; Exact sciences and technology; Limit of Detection; Other chromatographic methods; Phenols - analysis; Seawater - analysis; Single-drop microextraction; Seawater analysis; Single-drop microextraction; Dispersive liquid–liquid microextraction; Endocrine-disrupting phenols; Performance evaluation; Microanalysis; HPLC chromatography; Time; Liquid phase; Mixture; Chemical enrichment; Sample preparation; Efficiency; Detection limit; Extraction; Seawater; Sample; Use; Method; Bisphenol A; Phenol; Ultraviolet detector; Acetonitrile; Microextraction; Phenols; Syringe; Dispersive liquid-liquid microextraction
• ISSN: 0039-9140; 1873-3573; 1873-3573
• DOI: 10.1016/j.talanta.2009.09.057

Two liquid-phase microextraction procedures: single-drop microextraction (SDME) and dispersive liquid–liquid microextraction (DLLME), have been developed for the determination of several endocrine-disrupting phenols (EDPs) in seawaters, in combination with high-performance liquid chromatography (HPLC) with UV detection. The EDPs studied were bisphenol-A, 4-cumylphenol, 4-tertbutylphenol, 4-octylphenol and 4- n-nonylphenol. The optimized SDME method used 2.5 μL of decanol suspended at the tip of a micro-syringe immersed in 5 mL of seawater sample, and 60 min for the extraction time. The performance of the SDME is characterized for average relative recoveries of 102 ± 11%, precision values (RSD) < 9.4% (spiked level of 50 ng mL −1), and detection limits between 4 and 9 ng mL −1. The optimized DLLME method used 150 μL of a mixture acetonitrile:decanol (ratio 15.7, v/v), which is quickly added to 5 mL of seawater sample, then subjected to vortex during 4 min and centrifuged at 2000 rpm for another 5 min. The performance of the DLLME is characterized for average relative recoveries of 98.7 ± 3.7%, precision values (RSD) < 7.2% (spiked level of 20 ng mL −1), and detection limits between 0.2 and 1.6 ng mL −1. The efficiencies of both methods have also been compared with spiked real seawater samples. The DLLME method has shown to be a more efficient approach for the determination of EDPs in seawater matrices, presenting enrichment factors ranging from 123 to 275, average relative recoveries of 110 ± 11%, and precision values (RSD) < 14%, when using a real seawaters (spiked level of 3.5 ng mL −1).