title: The joint effects of room temperature ionic liquids and ordered media on fluorescence characteristics of estrogens in water and methanol.
abstract: This study investigated the steady-state and time-resolved fluorescence properties of 17α-ethinylestradiol (EE2) and 17β-estradiol (E2) in the presence of ordered media (β-cyclodextrins (β-CD) and cetyltrimethylammonium bromide (CTAB)). In addition, we analyzed the effects of four room temperature ionic liquids (RTILs) on the fluorescence intensities (FIs) of EE2/β-CD and E2/β-CD inclusion complexes in methanol. Both β-CD and CTAB enhanced the fluorescence of EE2 and E2. The FIs of EE2 and E2 with β-CD or CTAB in methanol were greater than those in water, possibly resulting from decreased oxygen-quenching in H2O molecules. β-CD and CTAB may form inclusion complexes with estrogen in both water and methanol. The inclusion ratio of the complex was 1:1 and the inclusion constant (K) values in water were greater than those in methanol. The fluorescence lifetimes were 2.50 and 4.13 ns for EE2 and 2.58 and 4.03 ns for E2 in aqueous solution and methanol, respectively. The changing trend of fluorescence lifetimes for EE2 and E2 in β-CD or CTAB was similar to the steady-state FIs. The four RTILs had a significant quenching effect on the FIs of EE2/β-CD and E2/β-CD, and the quenching process for EE2/β-CD and E2/β-CD by RTILs was demonstrated to be a dynamic quenching mechanism. Fluorescent data obtained from these complex systems provide a theoretical foundation for understanding the interaction mechanisms between ordered media and RTILs in the analysis of estrogens.
authors.affiliation: School of Life Sciences, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Huili
authors.initials: H
authors.lastname: Wang
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Ailian
authors.initials: A
authors.lastname: Duan
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China; Department of Land, Air and Water Resources, University of California, Davis, CA 95616, USA.
authors.forename: Randy A
authors.initials: RA
authors.lastname: Dahlgren
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Yanyan
authors.initials: Y
authors.lastname: Li
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Changli
authors.initials: C
authors.lastname: Li
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Wenwei
authors.initials: W
authors.lastname: Wang
authors.affiliation: School of Life Sciences, Wenzhou Medical University, Wenzhou 325035, China.
authors.forename: Aibing
authors.initials: A
authors.lastname: Zeng
authors.affiliation: Wenzhou Applied Technology & Environmental Research Institute, Wenzhou Medical University, Wenzhou 325035, China. Electronic address: zjuwxd@163.com.
authors.forename: Xuedong
authors.initials: X
authors.lastname: Wang
mesh_terms: D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry*; D004958:Estradiol / Q000737:chemistry*; D004997:Ethinyl Estradiol / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D014867:Water / Q000737:chemistry*; D047392:beta-Cyclodextrins / Q000737:chemistry*
chemical_list: D002593:Cetrimonium Compounds; D047392:beta-Cyclodextrins; D014867:Water; D004997:Ethinyl Estradiol; D004958:Estradiol; C031215:betadex; D000432:Methanol; D000077286:Cetrimonium
keywords: 17α-Ethinylestradiol; 17β-Estradiol; Cetyltrimethylammonium bromide; Fluorescence intensity; Inclusion complex; β-Cyclodextrins