title: Comparison of different mesoporous silicas for off-line solid phase extraction of 17β-estradiol from waters and its determination by HPLC-DAD.
abstract: Functionalized (SBA-C₁₈ and SM-C₁₈) and non-functionalized (SBA-15 and SM) mesoporous silicas were then examined as sorbents for solid-phase extraction of 17β-estradiol in aqueous media. Experiments were run in order to test critical factors affecting the procedure extraction efficiency, including the type of sorbent, the analyte concentration, the solvent and volume used for elution and the sample volume. Among the prepared materials, SBA-C₁₈ had the highest adsorption affinity towards 17β-estradiol and under optimized conditions (200mg of sorbent, 150 mL of water sample, elution with 3 × 2 mL of methanol) this sorbent proved good extraction capacity and elution efficiency for this hormone from aqueous media (recovery near 100%). To evaluate the analytical applicability of the proposed method, it was applied to the determination of 17β-estradiol in drinking water by high performance liquid chromatography with a photodiode array detector. Calibration curves were shown to be linear between 1.25 and 100 mg L(-1)with correlation coefficients ≥0.999 (n=5) for 17β-estradiol. The instrumental detection and quantitation limits calculated were 0.38 and 1.25 mg L(-1), respectively. The relative standard deviation obtained values were ≤3% and the mean recoveries obtained were of 82%. The results suggest that SBA-C18 is a promising material for the off-line solid phase extraction of 17β-estradiol from waters.
authors.affiliation: Departamento de Química Inorgánica y Analítica, ESCET, Universidad Rey Juan Carlos, C/Tulipán s/n, 28933 Móstoles, Madrid, Spain.
authors.forename: Judith
authors.initials: J
authors.lastname: Gañán
authors.forename: Damián
authors.initials: D
authors.lastname: Pérez-Quintanilla
authors.forename: Sonia
authors.initials: S
authors.lastname: Morante-Zarcero
authors.forename: Isabel
authors.initials: I
authors.lastname: Sierra
mesh_terms: D000327:Adsorption; D002138:Calibration; D002851:Chromatography, High Pressure Liquid; D004784:Environmental Monitoring; D004958:Estradiol / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010777:Photochemistry; D011312:Pressure; D015203:Reproducibility of Results; D012821:Silanes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D052616:Solid Phase Extraction; D012997:Solvents / Q000737:chemistry; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods; D014881:Water Supply; D014961:X-Ray Diffraction
chemical_list: C509969:SBA-15; D012821:Silanes; D012997:Solvents; D014874:Water Pollutants, Chemical; D014867:Water; C024779:octadecylsilane; D004958:Estradiol; D012822:Silicon Dioxide
keywords: 17β-Estradiol; 3-aminopropyltriethoxysilane; ACN; APTES; BET surface area; BJH; Barret–Joyner–Halenda; C(18); CTAB; DAD; DCM; FTIR; Fourier transform infrared; HPLC; K(ow); MeOH; Mesoporous silica; PTFE; RSD; S(BET); SEM; SPE; Solid-phase extraction; TEM; TEOS; TGA; Water; X-ray diffraction; XRD; acetonitrile; capacity factor; cetyltrimethylammonium bromide; dead time; dichloromethane; high performance liquid chromatography; k(w); k′; methanol; octadecyl-modified silica; octanol–water partition coefficient; photodiode array detector; polytetrafluoroethylene; relative standard deviation; retention factor in water; retention time; scanning electron microscopy; solid-phase extraction; t(0); t(r); tetraethylorthosilicate; thermogravimetric analysis; transmission electron micrograph