焦化柴油中酚类化合物的分离分析

采用碱液抽提法对四种不同产地的焦化柴油中的酸性物进行了分析。气相色谱-质谱联用(GC-MS)分析结果表明,酸性物中含有微量的小分子硫醇和硫醚,酚类化合物占90%以上,同时还含有少量的苯硫酚衍生物。对比分析结果表明,延迟焦化原料渣油中硫含量越高,对应的焦化柴油中苯硫酚衍生物含量越高。针对从辽阳石化焦化柴油中提取的酸性物,对其在300℃之前进行常压蒸馏切割成5个不同馏分段,对每一个馏分段逐一进行GC-MS分析,总计鉴定出38种物质,其中小分子硫醇和硫醚7种,苯酚衍生物24种,萘酚衍生物6种。焦化柴油中酚类化合物来源与减压渣油中含氧量以及烷基芳基醚含氧结构有关。     

酚醛模塑料在汽车轻量化中的应用

简要概括了汽车轻量化技术发展状况及其实现方法,介绍了酚醛模塑料及其成型工艺。同时详细讨论了酚醛模塑料在汽车刹车系统和发动机等部件中的应用以及酚醛模塑料在汽车应用中存在的问题。     

Antioxidant Properties of Phenolic Lignin Model Compounds

Antioxidant activities of phenolic lignin model compounds were determined by measurements of inhibition rate constants (k_inh) during inhibited peroxidation of styrene in chlorobenzene initiated by azobisisobutyrylnitrile with known rates of initiation (R_i). The number of peroxyl radicals trapped by each antioxidant, the stoichiometric factors (n), were determined by comparison with pentamethyl-hydroxychroman, PMHC, n = 2. Monomeric lignin models, 4-propylguaiacol (1), eugenol (2), isoeugenol (3), coniferyl alcohol (4), coniferyl aldehyde (5), and 4-allyl-2,6-dimethoxyphenol (6) were all more active antioxidants than the commercial inhibitor 2,6-di-tert-butyl-4-methylphenol (BHT). Two dimer models, bis(2-hydroxy-3-methoxyl-5-allylphenyl)methane (7) and 2,2′-dihydroxy-3,3′-dimethoxy-5,5′-dimethoxymethylbiphenyl (8) and a synthetic tetramer, bis[2-hydroxy-5-(2′-hydroxy-3′-methoxy-5′-methylbenzyl)-3-methoxyphenyl]methane (9) were more active antioxidants. The overall relative activity was tetramer > dimers > monomers > BHT. The stoichiometric factors of 1 to 6 ranged from 1.6 to 1.7 compared to PMHC. The n factors for 7, 8, and 9, showed an additive effect per phenolic hydroxyl. Phenolic groups in lignin may protect lignin-containing pulps and paper against damaging free radical peroxidation.     

Microwave-Assisted Extraction of Phenolic Compounds from Caper

In this study, it was aimed to extract phenolic compounds from caper by using microwave and to compare the results with conventional extraction. For microwave-assisted extraction, power, extraction time, solid to solvent ratio, and solvent type were selected as independent variables. Dependent variables were total phenolic content (TPC), antioxidant activity, and concentration of phenolic compounds. The increase in solvent amount increased TPC. The highest TPC was obtained by using extraction conditions of 5 min at 400 W, solid to solvent ratio of 1:30, and ethanol-water mixture at a ratio of 50:50. There was no significant difference between microwave and conventional extraction on TPC and antioxidant activity (AA). However, microwave-assisted extraction decreased extraction time significantly.     

Perstraction of Phenolic Compounds from Aqueous Solution Using a Nonporous Membrane

Abstract

An exploratory study of nondispersive extraction of various phenolic solutes using a nonporous membrane has been carried out. Sorption and permeation data for these solutes have been obtained using a silicone rubber membrane. The effects of hydrodynamic factors, concentration of phenols, and temperature on the trans-membrane flux are discussed. A film model is used to determine the intrinsic mass transfer characteristics of the membrane. Comparison of sorption of phenolic solutes from the membrane into the organic solvent indicates that methyl isobutyl ketone is a better solvent than butyl acetate.     

Antioxidative and Bactericidal Properties of Phenolic Compounds in Rapeseeds

Antioxidative and bactericidal properties were investigated in isolated and fractionated phenolic compounds of rapeseeds. Among the investigated groups of compounds (phenolic acids, sinapine and the products of its hydrolysis) phenolic acids, and especially sinapic acid, were found to be the most active. Due to valuable properties of these compounds they can be considered to be applied for food and fodder preserving.     

Variation in Phenolic Compounds within a Birch (Betula pendula) Population

In previous studies, the qualitative and quantitative variation found in defense chemistry among birch populations and even among individual clones has been considerable. However, information about variation among adult, naturally regenerated birch trees from natural populations is still lacking. In this study, the phenolic composition of leaves of 30 naturally regenerated 20-year-old birch (Betula pendula) trees was analyzed for two successive years in order to characterize the chemical composition of individual trees, analyze the annual variation, and determine chemical similarities among individual trees within a population. The main phenolic compounds were flavonoid glycosides, myricetin, and quercetin derivatives. Annual variation in concentration among leaves was large. In most trees, concentrations were markedly higher in 1998 than in 1997; for certain compounds, the detected increase was as much as a 50%. However, for some individual trees, there were no differences between years in chemical quantity. Thus, when selection or grouping of trees is based on secondary chemistry, quantitative variation should be considered carefully. With the qualitative UPGMA method of classification, four chemotypes were found. The grouping was similar for both years, and qualitatively the results of an individual tree seem to be independent of sampling year. The stability in chemical profile of individual trees suggests that quality is tightly controlled by genotype, which provides a recognition tool for chemotaxonomy. The high within-population variation found in leaf defense chemistry may provide protection against different types of insects (generalists or specialists) and, thus, have positive effects on population survival.     

高效液相色谱法测定酚类化合物

高效液相色谱法（HPLC）测定了饮用水和地面水中的酚类污染物。水样前处理用固相萃取法,经过比较,选择了回收率较高的小柱,用紫外分光光度检测器测定了方法的精密度、准确度和检出限。方法具有重现性好、选择性好、灵敏度高、操作简便的优点。     

化学法降解木质素为酚类化合物的研究进展

木质素是一种具有潜在巨大应用前景的可再生资源,其降解的酚类化合物产物是可替代部分仅依靠石油能源为主要来源的化工原料,故可缓解一定的石油能源压力。主要从化学法降解木质素的方法和防止降解物重聚两个角度综述木质素降解的研究现状,总结木质素降解存在的主要问题及对其未来的发展提出了展望。     

奶粉中苯酚类污染物残留量检测方法研究

建立气相色谱法检测奶粉中苯酚类污染物残留的分析方法,样品经过酸性水溶液提取,采用正己烷萃取,碳酸钾溶液反萃取,乙酸酐衍生,GC-ECD法同时检测,外标法定量,阳性样品采用GC/MS确证,方法回收率为75.8%~93.5%,RSD为2.61%~4.88%,方法检测限为:0.8~.3.0μg/kg。     

Characterisation of Phenolic Compounds in Oils Produced from Frosted Olives

Frost is one of the most important weather related hazards for the Australian olive industry and it has caused significant economic losses during the last decade. Its impact on oil quality was significant in 2006 with more than 20% of Australian oil of that year being affected to some degree. Early frosts will normally affect the fruit leading to significant changes in the chemical and organoleptic characteristics of the oils. The aim of this work was to study the effect of freeze damage on the phenolic composition and quality parameters of oils from three different varieties: Frantoio, Barnea and Picual. Quality chemical parameters showed significant differences in oils produced from fruit that was frozen for 2 and 4 weeks. Those chemical parameters were not significantly different in the oil produced from fruit immediately after being frosted. Nonetheless, the sensorial profile and the polyphenols showed significant changes even with oils produced within a short time after the freezing event. Those changes became more evident with the oils produced at increasing time from the moment of fruit freezing.     

Acrylamides as Phenolic Antioxidants for Acrylqnitrile-Butadiene Rubber Compounds

A number of phenolic antioxidants were prepared using the reaction between acridly chloride and o-, m-, and p-amino phenols. These antioxidants were used in acrylonitrile-butadiene rubber compounds to achieve better products for various sealing applications. Several techniques were used to evaluate the prepared antioxidants and the processed rubber compounds.     

高效液相色谱法测定酚类化合物探讨

基于环境保护要求,对存在的酚类化合物含量进行测定,作为下一步控制措施选择以及方案制定的依据。将高效液相色谱法作为技术对象,分析了其在酚类化合物测定中的应用要点。     

去除水环境中酚类内分泌干扰物的研究进展

就水环境中两种酚类内分泌干扰物——壬基酚和双酚A的来源、性质及污染情况进行综述,指出了开展内分泌干扰物研究的重要性,并着重对其降解去除方法进行了研究。提出了今后的研究方向,认为树脂吸附法是一种很有前途的去除酚类内分泌干扰物质的方法。     

酚醛模塑料改性及成型工艺研究进展

综述了酚醛模塑料及其成型工艺的研究进展。酚醛模塑料的改性方法主要包括基体树脂改性和填充改性,其中基体树脂改性可细分为结构改性、共聚改性和共混改性等。介绍了酚醛模塑料的主要成型工艺,包括模压成型工艺和注射成型工艺。分析了后固化处理工艺对产品性能的影响,并对今后的发展趋势进行了展望。     

Antioxidant Activity of Added Phenolic Compounds in Freeze-Dried Microencapsulated Sunflower Oil

This study was aimed at evaluating the effectiveness of phenolic antioxidants with a similar structure but having a different polarity in dried microencapsulated sunflower oil. The antioxidants tested were, on one hand, α-tocopherol and its water soluble analogue, Trolox, and on the other, gallic acid and its ester derivatives, propyl gallate and dodecyl gallate. At a moderate temperature (40 °C), the samples were oxidized under accelerated conditions by using Cu(II) as an oxidation catalyst. The progress of oxidation was followed up over time in the free and encapsulated oil fractions. The peroxide value, the total content of polymers and, when appropriate, the content of α-tocopherol were determined. Quantitative analysis of the total fraction of the non-volatile oxidation products and their distribution in oligomers, dimers and monomers was applied to samples to obtain a complete evaluation of oxidation. Finally, as a complementary measure, the antioxidants were also assessed by direct application of the Rancimat test at 100 °C on the dried microencapsulated oil samples. Results showed that the antioxidants of lower polarity in each series, i.e. tocopherol and dodecyl gallate, were to a great extent the most protective antioxidants. The results obtained by the Rancimat test were consistent with those found during oxidation at moderate temperature. Furthermore, the addition of Cu(II) reduced proportionally the oxidative stability index of the dried microencapsulated samples.     

烟草和烟气中酚类物质检测技术研究进展

烟草中的多酚类物质(如绿原酸、芸香苷和莨菪亭)对烟草品质有重要影响,卷烟烟气中的简单酚类物质(如邻、间、对-苯二酚、苯酚、邻、间、对-甲酚)是烟气主要有害成分之一;烟草和烟气中酚类物质的分析检测及其相互转化规律一直是国内外烟草行业研究的热点方向之一。总结了近年来烟草中主要的多酚物质和烟气中主要的简单酚的分析检测方法以及多酚与简单酚之间的转化研究进展。     

Analysis of Phenolic Compounds and Antioxidant Activity in Wild Blackberry Fruits

Twenty three different wild blackberry fruit samples were assessed regarding their phenolic profiles and contents (by LC/MS quadrupole time-of-flight (QTOF) and antioxidant activity (ferric reducing ability of plasma (FRAP) and 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS)) by two different extraction methods. Thirty four phenolic compounds were detected (8 anthocyanins, 15 flavonols, 3 hydroxycinnamic acids, 6 ellagic acid derivatives and 2 flavones). In samples, where pressurized liquid extraction (PLE) was used for extraction, a greater increase in yields of phenolic compounds was observed, especially in ellagic acid derivatives (max. 59%), flavonols (max. 44%) and anthocyanins (max. 29%), than after extraction by the ultrasonic technique extraction (UAE) method. The content of phenolic compounds was significantly correlated with the antioxidant activity of the analyzed samples. Principal component analysis (PCA) revealed that the PLE method was more suitable for the quantitative extraction of flavonols, while the UAE method was for hydroxycinnamic acids.     

超声波辅助提取菠萝皮渣中多酚的工艺优化

为确定菠萝皮中多酚化合物超声提取的最佳工艺参数,以菠萝下脚料菠萝皮为主要原料,通过正交试验优化了菠萝皮中多酚化合物的超声波辅助提取工艺条件,即:细度50目、液料比35:1(m L/g)、超声提取功率250W、乙醇浓度50%以及超声提取时间55min。采用此最佳提取工艺进行试验,获得的菠萝皮渣中多酚提取量达到13.84(mg/g)。