Influence of β-cyclodextrin complexation on photochemistry of bisphenols in aqueous solutions

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Application of Molecularly Imprinted Polymers in the Analysis of Waters and Wastewaters

The increase of the global population and shortage of renewable water resources urges the development of possible remedies to improve the quality and reusability of waste and contaminated water supplies. Different water pollutants, such as heavy metals, dyes, pesticides, endocrine disrupting compounds (EDCs), and pharmaceuticals, are produced through continuous technical and industrial developments that are emerging with the increasing population. Molecularly imprinted polymers (MIPs) represent a class of synthetic receptors that can be produced from different types of polymerization reactions between a target template and functional monomer(s), having functional groups specifically interacting with the template; such interactions can be tailored according to the purpose of designing the polymer and based on the nature of the target compounds. The removal of the template using suitable knocking out agents renders a recognition cavity that can specifically rebind to the target template which is the main mechanism of the applicability of MIPs in electrochemical sensors and as solid phase extraction sorbents. MIPs have unique properties in terms of stability, selectivity, and resistance to acids and bases besides being of low cost and simple to prepare; thus, they are excellent materials to be used for water analysis. The current review represents the different applications of MIPs in the past five years for the detection of different classes of water and wastewater contaminants and possible approaches for future applications.     

Novel sponge-like molecularly imprinted mesoporous silica material for selective isolation of bisphenol A and its analogues from sediment extracts

Bisphenol A (BPA) imprinted sponge mesoporous silica was synthesized using a combination of semi-covalent molecular imprinting and simple self-assembly process. The molecularly imprinted sponge mesoporous silica (MISMS) material obtained was characterized by FT-IR, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption–desorption measurements. The results show that the MISMS possessed a large specific surface area (850.55 m² g⁻¹) and a highly interconnected 3-D porous network. As a result, the MISMS demonstrated a superior specific adsorption capacity of 169.22 μmol g⁻¹ and fast adsorption kinetics (reaching equilibrium within 3 min) for BPA. Good class selectivity for BPA and its analogues (bisphenol F, bisphenol B, bisphenol E and bisphenol AF) was also demonstrated by the sorption experiment. The MISMS as solid-phase extraction (SPE) material was then evaluated for isolation and clean-up of these bisphenols (BPs) from sediment samples. An accurate and sensitive analytical method based on the MISMS–SPE coupled with HPLC–DAD has been successfully established for simultaneous determination of five BPs in river sediments with detection limits of 0.43–0.71 ng g⁻¹ dry weight (dw). The recoveries of BPs for lyophilizated sediment samples at two spiking levels (50 and 500 ng g⁻¹ dw for each BP) were in the range of 75.5–105.5% with RSD values below 7.5%.     

Simple high-performance liquid chromatography-ultraviolet method for simultaneous separation and detection of 14 bisphenol pollutants in building materials

A high-performance liquid chromatography-ultraviolet method was developed for rapidly and simultaneously analyzing novel and typical bisphenols in building materials, including bisphenol S, diphenolic acid, bisphenol F, bisphenol E, bisphenol A, bisphenol B, bisphenol AF, bisphenol AP, bisphenol C, bisphenol FL, bisphenol Z, bisphenol BP, bisphenol M, and bisphenol P. By using a Kromasil 100–5 C18 column, these bisphenols were completely separated in 40 min via gradually increasing the concentration of methanol in the mobile phase from 45 to 80% during the elution process. In particular, this method achieved the synchronous analysis of bisphenol S, diphenolic acid, bisphenol FL, bisphenol BP, and bisphenol M through HPLC, which were difficult to separate and had to be identified and detected through mass spectrometry. The limits of detection of the method ranged from 0.002 to 0.040 mg/L for these 14 bisphenols, with a precision of less than 4.9% (n = 7, c = 0.05 mg/L). The analytical results for five types of building materials (phenolic, epoxy, polycarbonate, polyester, and polysulfone resins) indicated that the proposed method is appropriated for the rapid measurement of bisphenols in real samples.     

热致性共聚酯液晶的研究——以双酚-对苯二甲酸酯为间隔段

热致性共聚酯液晶由于具有优异的热、机械及加工等性能,引起人们对其应用及基础研究的重视。本实验室曾对以不同长度碳链为软间隔段的共聚酯进行了研究,在产物介晶单元含量不高(约20％)时即可表现出明显液晶性。本文选用以双酚A(BPA)或双酚S(BPS)-对苯二甲酸酯为间隔段进行了研究。     

Preparation of copolyesters from diols and bisphenols by the solution polycondensation with TsCl/DMF/Py as a condensing agent

A novel synthetic method for the preparation of copolyesters comprised of diols and bisphenols using tosyl chloride (TsCl)/DMF/pyridine (Py) as a condensing agent has been developed. A variety of combinations of monomers could produce relatively high molecular weight copolymers, and better results were obtained by initial oligomerization of diols followed by bisphenols. In order to demonstrate usefulness of this method, copolymers comprised of IPA/TPA (50/50), bis(2‐hydroxyethyl)terephthalate (BHET),and several bisphenols were prepared and compared to the poly(ethylene terephthalate) (PET) modified by TPA and 2,2‐bis(4‐hydroxyphenyl)propane (BPA) diacetate in terms of their thermal properties. The length of mesogenic unit segments in the thermotropic IPA/TPA (50/50)‐BHET/ 4,4′‐dihydroxybenzophenone (4,4′‐DHBP) (50/50) copolymer was changed by initial reaction of BHET followed by dropwise addition of 4,4′‐DHBP in the two‐stage polycondensation and also by varying the amounts of BHET used at the initial and final stages in the three‐stage copolycondensation, and the results were studied by NMR and their thermal properties. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1270–1276, 2000     

Application of d-SPE before SPE and HPLC-FLD to Analyze Bisphenols in Human Breast Milk Samples

In this study, we propose a simple, cost-effective, and sensitive high-performance liquid chromatography with fluorescence detection (HPLC-FLD) for the simultaneous determination of seven bisphenols (bisphenol F (BPF), bisphenol E (BPE), bisphenol B (BPB), BADGE (bisphenol A diglycidyl ether), BADGE∙2H₂O, BADGE∙H₂O, BADGE∙2HCl) in human breast milk samples. The dispersive solid phase extraction (d-SPE) coupled with solid phase extraction (SPE) procedure performed well for the majority of the analytes with recoveries in the range 57–88% and relative standard deviations (RSD%) of less than 9.4%. During the d-SPE stage, no significant matrix effect was observed thanks to the application of different pairs of salts such as zirconium-dioxide-based sorbents (Z-Sep or Z-Sep +) and primary secondary amine (PSA) or QuEChERS Enhanced Matrix Removal-Lipid (EMR-Lipid) and PSA. The method limits of quantification (mLOQs) for all investigated analytes were set at satisfactory low values in the range 171.89–235.11 ng mL⁻¹. Analyte concentrations were determined as the average value from human breast milk matrix samples. The results show that the d-SPE/SPE procedure, especially with the application of EMR-Lipid and PSA, could be used for further bisphenol analyses in human breast milk samples.     

食品及环境样品中双酚类物质的前处理及检测方法研究进展

双酚类物质作为一种环境内分泌干扰物,广泛存在于食品包装材料及环境介质中,对生态环境造成污染,也对人体健康产生一定危害。双酚残留是目前重要的食品安全问题,检测食品和环境样品中的双酚类物质的含量对人体健康具有重要的意义。由于残留目标物浓度通常较低,且实际样品存在基质干扰,因此需经一定的样品前处理,并结合仪器分析方法,提高检测效率,增强分析灵敏度与可靠性。常用的前处理分析方法主要有液液萃取、微波辅助萃取、固相萃取、固相微萃取、基质分散固相萃取、QuEChERS等,常用仪器分析方法包括液相色谱法、气相色谱法、毛细管电泳法、酶联免疫吸附测定法、生物传感器法等。该文综述了食品及环境样品中双酚类物质的样品前处理及仪器分析方法,为双酚类化合物的残留监测提供了参考依据。     

Synthesis and properties of aromatic poly (ether sulfone)s and poly (ether ketone)s based on methyl-substituted biphenyl-4,4′-diols

Novel methyl-substituted aromatic poly (ether sulfone)s and poly (ether ketone)s were synthesized from combinations of 3,3′,5,5′-tetramethylbipheny-4,4′-diol and 2,2′,3,3′,5,5′-hexamethylbiphenyl-4,4′-diol, and 4,4′-dichlorodiphenyl sulfone and 4,4′-difluorobenzo-phenone by nucleophilic aromatic substitution polycondensation. The polycondensations proceeded quantitatively in a N-methyl-2-pyrrolidone-toluene solvent system in the presence of anhydrous potassium carbonate to afford the polymers with inherent viscosities between 0.86 and 1.55 dL/g. The methyl-substituted poly (ether sulfone)s and poly (ether ketone)s showed good solubility in common organic solvents such as chloroform, tetrahydrofuran, pyridine, m-cresol, and N,N-dimethylacetamide. The tetramethyl- and hexamethyl-substituted aromatic polyethers had higher glass transition temperatures than the corresponding unsubstituted polymers, and did not decompose below 350°C in both air and nitrogen atmospheres. The films of the methyl-substituted poly (ether ketone)s became insoluble in chloroform by the irradiation of ultraviolet light, indicating the occurrence of photochemical crosslinking reactions. © 1994 John Wiley & Sons, Inc.     

超临界流体色谱法同时测定海洋水体及沉积物中的4种双酚

在超临界流体色谱分析条件下,建立了由液液萃取与超临界流体色谱（supercritical fluid chromatography,SFC）同时测定海洋水体中双酚A（BPAF）、双酚AF（BPA）、双酚C（BPC）、四溴双酚A（TBBPA）4种内分泌干扰物的方法。实验结果表明,当SFC流动相为超临界态二氧化碳和甲醇,检测波长为230 nm,柱温为36 ℃、流速为2.0 mL·min^-1、系统背压为12 MPa时,5 min内即可实现对双酚类化合物的分离。在线性浓度范围内,双酚类化合物的线性相关系数均高于0.998 9,检出限为0.03~0.06 mg·L^-1,4种双酚类化合物在实际样品中的加标回收率为85.7%~112.0%,相对标准偏差均小于10.3%。本文方法可简便快速地检测海洋水体中的双酚,灵敏度和选择性较高,对研究和追踪海洋环境中双酚类化合物的分布具有重要意义。