β-Ketoenamine-linked covalent organic framework absorbent for online micro-solid phase extraction of trace levels bisphenols in plastic samples

Covalent organic frameworks with tunable porous crystallinity and outstanding stability have exhibited fascinating pretreatment performance as ideal extraction media. Herein, the β-ketoenamine-linked TpPa-1 synthesized by 1,3,5-triformylphloroglucinol and paraphenylenediamine was employed as the absorbent for online micro-solid phase extraction of trace bisphenols combined with high-performance liquid chromatography detection. A series of characterizations indicated that the TpPa-1 possessed large surface areas, high stability, and hydrophobicity. The main experimental parameters affecting the extraction efficiency were optimized in detail. Compared with four commercial sorbents, the TpPa-1 exhibited superior enrichment capacity for extracting bisphenols. Under the optimum conditions, the established method demonstrated a wide linear range and high sensitivity with the limit of detection ranging from 0.05–0.06 μg/L. Furthermore, the developed method was successfully applied to determine bisphenols in plastic samples. Bisphenol A was actually detected in a transparent box with a concentration of 0.31 μg/g, and the recoveries of the four bisphenols in the plastic samples were 80.5–116% with the relative standard deviation less than 9.2%. Such performance was attributed to recognition affinity, including the π-π affinity, hydrophobic effect, and hydrogen bond. These results demonstrated that TpPa-1 possessed great potential to be an excellent pretreatment medium for online separation and analysis of trace analytes in complex samples.     

A facile cesium fluoride-mediated synthesis of aromatic polyethers from bisphenols and activated aromatic dihalides

A facile method for the synthesis of high-molecular-weight aromatic polyethers was developed with the use of cesium fluoride as a base. The high-temperature solution polycondensation between bisphenols and activated aromatic dihalides with cesium fluoride in polar aprotic solvents readily afforded a series of aromatic polyethers having inherent viscosities of 0.5–1.0 dL/g under essentially neutral and milder reaction conditions, compared with the conventinal method using alkali hydroxides or alkali carbonates. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 2055–2061, 1997     

BULK AND INTERFACIAL BEHAVIORS OF MIXED SYSTEM OF HEXADECYLPYRIDINIUM CHLORIDE AND Na+ 2-HYDROXY BENZOATE−

The micellization behavior of hexadecylpyridinium chloride usually called cetylpyridinium chloride (CPC) in presence of sodium salicylate ( NaSal) has been investigated. The surface tension, conductance and microcalorimetric methods have been employed to determine the critical micellar concentration (CMC) of CPC and NaSal mixed in different molar proportions. The interfacial area occupied by CPC in presence of NaSal, the free energy of adsorption and the energetics of micellizatton have been evaluated. The enthalpy of interaction of NaSal with CPC micelle has also been estimated from microcalorimetric measurements. The shear viscosity of the CPC-NaSal combination at equimolar proportion at different surfactant concentration and temperature, and also the shear viscosity of CPC-NaSal combination at different molarity ratios with a fixed surfactant concentration have been determined. The static and dynamic light scattering measurements of the CPC-NaSal system at different composition and in presence of NaCl have been reported. Worm-like micelles of concentration dependent dimension and intermicellar repulsive interaction have been envisaged.     

Determination of four bisphenols in water and urine samples by magnetic dispersive solid‐phase extraction using a modified zeolite/iron oxide composite prior to liquid chromatography diode array detection

A novel approach is presented to determine four bisphenols in water and urine samples, employing magnetic dispersive solid‐phase extraction combined with liquid chromatography and diode array detection. A modified zeolite‐based magnetic composite was used as an efficient sorbent, combining the advantages of magnetic materials with the remarkable properties of zeolites. A multivariate optimization design was employed to optimize some experimental factors affecting magnetic dispersive solid‐phase extraction. The method was evaluated under optimized conditions (i.e., amount of sorbent, 50 mg; sample pH, unadjusted; NaCl concentration, 1.25%; extraction and elution time, 2 min; eluent solvent, ethanol; eluent solvent volume, 400 µL), obtaining good linearity with correlation coefficients ranging between 0.995 and 0.999 (N = 5) (from 2 to 250 µg/L for bisphenol A, bisphenol AP, and bisphenol P and from 5 to 250 µg/L for bisphenol AF). Method repeatability was assessed obtaining coefficients of variation between 3 and 11% (n = 6). Finally, the method was applied to spiked real samples, obtaining for water samples relative recoveries between 83 and 105%, and for urine samples between 81 and 108% for bisphenol A, bisphenol AP, and bisphenol AF, and between 47 and 59% for bisphenol P.     

超高效液相色谱-串联质谱法同时测定塑料包装矿泉水中11种双酚类化合物

建立了同时测定塑料包装矿泉水中11种双酚类化合物的超高效液相色谱-串联质谱（UPLC-MS/MS）分析方法。以真空冷冻干燥的方法对样品进行前处理。使用Waters ACQUITY UPLC BEH C₁₈色谱柱（100 mm×2.1 mm,1.7 μm）进行分离,以甲醇和0.1%（v/v）氨水为流动相对目标物进行梯度洗脱。在电喷雾负离子模式及多反应监测（MRM）模式下进行定性和定量分析。结果表明,11种双酚类化合物在线性范围内线性关系良好,线性相关系数（R²）均大于0.997;目标物的检出限为0.01~1.00 μg/L;3个加标水平下的回收率为75.3%~102.1%,相对标准偏差为1.5%~8.9%。本方法准确、简便、快速,可用于塑料包装矿泉水中双酚类化合物的实际检测。     

Hydrogen-bonded self-assembly of pyridinium and anilinium bisphenols mediated by the hydrogen difluoride ion: towards control of C-H...pi (aromatic) interactions

The role of C-H...pi and C-H...O interactions in HF(2)(-)-assisted self-assembly of nitrogen-containing bisphenols are investigated. Unusual control on the end-face and edge-face geometries of aromatic C-H...pi interactions by a water molecule in the 4-[(4-hydroxy-3,5-dimethylphenyl)methyl]pyridinium difluoride lattice is observed. The bis(4-hydroxy-3,5-dimethylphenyl)(4-ammoniophenyl)methane.HF(2)(-) self-assembles through the formation of hydrogen-bonded cyclic hexamers.     

Fabrication of glucose‐derived carbon‐decorated magnetic microspheres for extraction of bisphenols from water and tea drinks

Glucose‐derived carbon‐decorated magnetic microspheres were synthesized by an easy hydrothermal carbonization method and used as a high‐efficiency adsorbent to extract bisphenols in water and tea drinks. The as‐prepared carbon‐decorated magnetic microspheres had a well‐defined core–shell structure with a shell thickness of about 5 nm. The microspheres possessed high saturation magnetization at 60.8 emu/g and excellent chemical stability in aqueous solution. The experimental parameters affecting the extraction efficiency, including extraction time, pH, adsorbent dosage, desorption solvents, desorption time, and solution volume were evaluated. Electrostatic and π–π interactions were the major driving forces during extraction. Overall, a new magnetic solid‐phase extraction method of determining bisphenols was developed on the basis of as‐prepared magnetic microspheres. The method had a wide linear range, low limits of detection (0.03–0.10 µg/L), and high recoveries (85.4–104.6%).     

卤代双酚与PXCl3关环反应的研究

根据溶剂效应,选择合适的溶剂,合成了2,4,8,10－四氯－12H－双苯并[d,g][1,3,2]－二氧磷杂（硫代）磷酰氯,首次合成并纯化得到了2,4,8,10－四氯－12H－双苯并[d,g][1,3,2]－二氧磷杂（硫代）磷酰氯。     

Monitoring of Pollutants Content in Bottled and Tap Drinking Water in Italy

The concentration levels of thirteen organic pollutants and selected heavy metals were investigated in 40 plastics bottled and tap water samples. Some of the selected contaminants have an ascertained or suspected endocrine disrupting activity, such as Bisphenol A (BPA) and its analogs, and Bis 2-ethylhexyl phthalate (DEHP), which are used by industries as plasticizers. The most frequently detected pollutants were Bisphenol AF (BPAF) (detection frequency (DF) = 67.5%, mean 387.21 ng L⁻¹), DEHP (DF = 62.5%, mean 46.19 µg L⁻¹) and BPA (DF = 60.0%, mean 458.57 ng L⁻¹), with higher concentration levels found in tap waters. Furthermore, a possible level of exposure to thirteen pollutants via drinking water intake was calculated. Our findings show that, even though the occurrence of contaminants and heavy metals in drinking waters does not pose an immediate, acute health risk for the population, their levels should be constantly monitored and “hard-wired” into everyday practice. Indeed, the health impact to the continuous and simultaneous intake of a huge variety of xenobiotics from various sources by humans is complex and still not fully understood.     

Photolysis of bisphenol‐based polyurethanes in solution

Photolysis of bisphenol‐based polyurethanes, using bisphenols A, S, and AF with methylene diphenyl diisocyanate (MDI), has been shown by the observed changes in fluorescence spectra, reduced viscosity, and UV absorbance. Analysis of the fluorescence spectra of model compounds and polymers showed that para‐photo‐Fries and cleavage‐type products were the major components formed during photolysis. The reduced viscosity and UV absorbance changes are consistent with a two‐step photodegradation process. The reduced viscosity changes indicate that oxygen inhibition on the cleavage process is more significant for bisphenol S‐based polyurethanes than for bisphenol A‐ and bisphenol AF‐based polyurethanes. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1331–1339, 1999