title: Determination of steroid sex hormones in real matrices by bar adsorptive microextraction (BAμE).
abstract: In the present work, the development of a novel analytical approach which combines a miniaturized bar adsorptive microextraction device with a micro-liquid desorption in one single step, followed by high performance liquid chromatography with diode array detection (BAµE-µLD/HPLC-DAD), is proposed for the determination of trace levels of nine steroid hormones (estriol, 17ß-estradiol, 17α-estradiol, 19-northisterone, 17α-ethynylestradiol, estrone, D-(-)-norgestrel, progesterone and mestranol) in environmental and biological matrices. From the comparison of ten different coating phases (five polymeric and five activated carbon sorbents), the modified pyrrolidone polymer (P2) showed the best compromise between selectivity and efficiency. Assays performed through BAµE(P2, 1.3mg)-µLD(100µL)/HPLC-DAD on 25mL of ultrapure water samples spiked at the 6.0μg/L level, yielded recoveries ranging from 93±9% to 101±8%, under optimized experimental conditions. The analytical performance showed convenient detection (50.0-100.0ng/L) and quantification limits (165.0-330.0ng/L), as well as good linear dynamic ranges (0.2-24.0µg/L) with remarkable determination coefficients (r(2)>0.9968). Excellent repeatability were also achieved through intraday (RSD<14%) and interday (RSD<12%) experiments. The application of the proposed analytical approach on environmental water and urine samples, using the standard addition methodology (SAM), revealed good linearity and sensitivity at trace level, with the detection of some of the target compounds. In short, the miniaturization of the analytical device for microextraction combined with the minimization of the solvent volume for back-extraction in one single step demonstrated remarkable performance, increasing the enrichment factor, being simultaneously more easier to implement and environment friendly.
authors.affiliation: University of Lisbon, Faculty of Sciences, Chemistry and Biochemistry Department and Centre of Chemistry and Biochemistry, Campo Grande Ed. C8, 1749-016 Lisbon, Portugal.
authors.forename: C
authors.initials: C
authors.lastname: Almeida
authors.affiliation: University of Lisbon, Faculty of Sciences, Chemistry and Biochemistry Department and Centre of Chemistry and Biochemistry, Campo Grande Ed. C8, 1749-016 Lisbon, Portugal. Electronic address: nogueira@fc.ul.pt.
authors.forename: J M F
authors.initials: JM
authors.lastname: Nogueira
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods; D002851:Chromatography, High Pressure Liquid; D012739:Gonadal Steroid Hormones / Q000032:analysis* / Q000737:chemistry / Q000652:urine; D011760:Pyrrolidinones / Q000737:chemistry
chemical_list: D012739:Gonadal Steroid Hormones; D011760:Pyrrolidinones; D002244:Carbon
keywords: Floating sampling technology; High performance liquid chromatography; Sorbent phases; Steroid sex hormones; Urine matrices; Water matrices