title: Analysis of oestrogenic compounds in dairy products by hollow-fibre liquid-phase microextraction coupled to liquid chromatography.
abstract: In this work, the potential of a hollow-fibre liquid-phase microextraction (LPME)-based method has been studied and validated for the extraction of a group of nine oestrogenic compounds four of them being natural (oestriol, 17β-oestradiol, 17α-oestradiol and oestrone), four being synthetic (17α-ethynyloestradiol, diethylstilbestrol, dienestrol and hexestrol) and one metabolite (2-hydroxyoestradiol) in different dairy products (whole and skimmed natural yogurt, a probiotic yogurt-type drink and cheese). The methodology includes a prior protein precipitation with acidified acetonitrile for all samples and an additional defatting step with n-hexane for cheese, the matrix with the highest fat content. Later separation, determination and quantification were done by high-performance liquid chromatography coupled to a diode array detector and a fluorescence detector set in series. Calibration, sensitivity, precision and accuracy of the method were carried out in the selected matrices, providing good linearity, LODs in the low μg/kg or μg/L range, good precision and appropriate accuracy.
authors.affiliation: Departamento de Química Analítica, Nutrición y Bromatología, Facultad de Química, Universidad de La Laguna (ULL), Avenida Astrofísico Francisco Sánchez s/n°, 38206 La Laguna, Tenerife, Spain.
authors.forename: Bárbara
authors.initials: B
authors.lastname: Socas-Rodríguez
authors.forename: María
authors.initials: M
authors.lastname: Asensio-Ramos
authors.forename: Javier
authors.initials: J
authors.lastname: Hernández-Borges
authors.forename: Miguel Ángel
authors.initials: MÁ
authors.lastname: Rodríguez-Delgado
mesh_terms: D000818:Animals; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004967:Estrogens / Q000032:analysis* / Q000302:isolation & purification*; D005506:Food Contamination / Q000032:analysis; D059627:Liquid Phase Microextraction / Q000295:instrumentation / Q000379:methods*; D015014:Yogurt / Q000032:analysis*
chemical_list: D004967:Estrogens
keywords: High-performance liquid chromatography; Hollow-fibre liquid-phase microextraction; Milk derivatives; Oestrogens