广东遂溪泥煤蜡和云南寻甸褐煤蜡的化学组成研究

泥煤蜡和褐煤蜡的主要组成物为纯蜡和树脂物质。纯蜡经皂化和溶剂萃取分离,分离物分别用气相色谱和色谱一质谱联合检定,表明进溪泥煤蜡和寻甸褐煤腊中均含有C_(24)～C_(34)偶碳烷醇和C_(16)～C)(34)烷酸。树脂物经皂化和柱层析分离,所得的氯仿洗脱物经红外光谱和~1H校磁热振谱检定证明其中含有β-谷甾醇。泥煤蜡树脂物中的β-谷甾醇主要以α-型形式存在,而褐煤的则为β-型。此外,泥煤蜡树脂物中还检出有雌二醇和雌酚酮类物。     

褐煤蜡中树脂组分的化学研究：生物标志化合物

用气相色谱－质谱联用仪对吉林舒兰褐煤蜡树脂和云南寻甸褐煤蜡树脂,进行了生物标志化合物的研究。结果指出,三萜类化合物中含有四环三萜、五环三萜、芳香五环三萜和含氧化合物,其中以Ｃ２５Ａ,Ｂ,Ｃ,Ｄ环－四芳鸟散烷和Ｃ２５Ａ,Ｂ,Ｃ,Ｄ环－四芳奥利烷含量最高,舒兰树脂中这两种化合物的含量高于寻甸树脂约１０倍;无羁萜和３－氧代别桦木烷量亦以舒兰树脂占优势     

褐煤蜡树脂中多环芳烃组成的研究

采用气相色谱法对云南寻甸褐煤蜡树脂和吉林舒兰褐煤蜡树脂,进行了多环芳烃分布特征的研究,从树脂中鉴定出６８个化合物的同系物。两个树脂样均以菲系化合物占有优势,舒兰树脂中菲系列量约三倍于寻甸树脂的相应量     

大孔磺酸树脂催化合成α-松油基甲醚的研究

单萜基醚具有增加、修饰香味和香气的作用 ,可广泛应用于医药、食品、牙膏和香水等工业的调香 [1] .以固体酸催化单萜烯与脂肪醇直接反应制取单萜基醚 ,具有反应路线短、产物易于分离、无废酸排放等特点 ,符合绿色化学发展方向 .目前 ,一些学者选用分子筛催化剂对单萜烯的烷氧基化进行了研究 [2～ 4] ,我们以有机固体酸大孔磺酸树脂为催化剂 ,研究了 α-蒎烯的甲氧基化反应规律 .1实验部分1 .1材料和试剂将南开大学化工厂生产的高分子树脂进行专门处理得大孔磺酸树脂催化剂 ,测得其酸中心数为4mmol/g,使用前经 35 3K烘 2 4 h,置于干燥器中…     

冷却结晶法脱除粗褐煤蜡中树脂的研究

褐煤蜡主要是由蜡质、树脂和地沥青三种组分所组成的混合物,其中树脂对产品质量影响较大,常需预先加以除去。作者利用树脂在较低温度下能溶于多种溶剂的特性,用冷却结晶法对粗褐煤蜡脱树脂进行了研究。考察了粗褐煤蜡脱树脂的主要影响因素——含蜡苯溶液的浓度、冷却速率和最终冷却结晶温度等。研究结果表明,这是一种很有实用价值的脱树脂方法。     

固载杂多酸催化合成2,4-二甲基-2-(4-甲基-3-戊烯基)-1,3-二氧五环

环缩酮类香料化合物[1 3]是在催化剂存在下由相应的酮和多元醇经缩合反应而制得。已报道的催化剂有质子酸[1]、固体酸[2,3]和某些金属盐类[4～7]等。本文以大孔阳离子交换树脂固载磷钨酸催化6 甲基 5 庚烯 2 酮与1,2 丙二醇的缩合反应,催化剂活性高,且可重复使用,后处理简便。1　实验1 1　仪器和试剂ＷＹＡ 1Ｓ阿贝折光仪;ＰＥ 2400ＣＨＮ元素分析仪;ＰＥ 783红外光谱仪。6 甲基 5 庚烯 2 酮、1,2 丙二醇、钨酸钠、磷酸氢二钠、盐酸等均为分析纯;大孔阳离子交换树脂(Ｄ001 ＣＣ型)。1 2　制备1 2 1　催化剂　以二水钨酸钠和十二水磷酸氢…     

褐煤蜡树脂中多环芳烃组织的研究

采用气相色谱法对云南寻甸褐煤炭树脂和吉林舒兰褐煤蜡树脂,进行了多环芳烃分布特征的研究,从树脂中鉴定出６８个化合物的同系物。两个树脂样均以菲系化合物占有优势,舒兰树脂中菲系列量约三倍于寻甸树脂的相应量。     

褐煤在离子液体1-丁基-3-甲基咪唑氯盐中热溶及热溶产物的分离与分析

基于离子液体对煤的高效解聚性能,对先锋褐煤(XL)、锡林郭勒褐煤(XLGL)和胜利褐煤(SL)在离子液体1-丁基-3-甲基咪唑氯盐([Bmim]Cl)中的热溶性能进行了研究.同时,对XL在离子液体[Bmim]Cl中的热溶产物进行了分离,并对分离所得各组分进行了分析表征来研究褐煤的结构信息.研究发现,在相同条件下离子液体[Bmim]Cl对不同褐煤的萃取性能显著不同,其顺序为XL>SL>XLGL.先锋褐煤离子液体热溶物可分离为丙酮可溶物、吡啶可溶物和吡啶不溶物,其中,丙酮可溶物(AS)为15.9%、吡啶可溶物(PS)为56.0%、吡啶不溶物(PI) 为28.1%.分析表明,丙酮可溶物中含有长链的脂肪化合物及部分三环、四环等芳香化合物,吡啶可溶物和吡啶不溶物中大多以三环及五环芳香化合物的形式存在.     

PAR螯合树脂相光度法测定钯

树脂相光度法是一种灵敏、快速、简单的分离富集与测定同时进行的新型方法[1 ,2 ] 。该方法以离子交换树脂作载体 ,直接对显色树脂进行光度测定 ,避免了洗脱、分离等复杂过程 ,使灵敏度得到了很大提高 ,迄今为众多研究者关注[3] 。铂族金属钯的光度分析法报道较多[4] ,但迄今少见用树脂相光度法测定钯的报道。星野仁等[5 ,6] 指出在ＥＤＴＡ ＮａＯＨ 硼砂介质中 ,ＰＡＲ Ｐｄ(Ⅱ )配合物与十四烷基二甲基苄基氯化铵形成离子缔合物 ,该缔合物能被ＣＨＣｌ3定量萃取 ,其摩尔吸光系数为 3.2 9× 1 0 4 ,方国桢等[7] 确定了在ＥＤ ＴＡ ＮａＯ…     

粉状褐煤流化萃取褐煤蜡工艺开发研究

流化萃取褐煤蜡新工艺将散式流态化技术用于液固萃取过程,以溶剂为动力,携带煤粒,实现流化连续萃取。在实验室研究的基础上,完成了生产能力为100吨蜡/年的中间试验,提出了适宜的操作条件。用平均含蜡量7.15%、含水量约23%、灰分12%的寻甸褐煤为原料,萃取率达到65～70%,苯耗量0.46吨/吨蜡。所得产品蜡含水份1.12%,灰份0.3%,熔点84℃,苯不溶物0.61%,树脂21.16%,地沥青11.54%,酸值为35.50,皂化值为102.25。该试验为工业生产装置的设计提供了基础数据。     

反应温度对加氢残渣油四组分含量和结构的影响

以沙轻减渣为原料,在高压釜内研究了不同反应温度下加氢反应前后渣油的四组分含量及其结构组成变化。结果表明,加氢残渣油中的饱和分含量明显增加,而芳香分和胶质的含量均降低,四组分含量随反应温度的升高均呈现规律性变化。加氢后四组分的H/C摩尔比和平均相对分子质量均降低,芳碳分率增加。随反应温度升高,四组分的H/C摩尔比和平均相对分子质量降低,烷基碳分率降低;芳香分、胶质和沥青质的芳碳分率增加;胶质和沥青质的总环数和芳环数均降低。渣油加氢过程中四组分都发生了明显的氢解和脱烷基反应。加氢反应中,胶质和沥青质结构单元间的各种桥键可发生明显地断裂,导致其结构单元数减少,且结构单元数随反应温度的升高而减少。     

Analysis and aging of unsaturated polyester resins in contemporary art installations by NMR spectroscopy

Two original art installations constructed from unsaturated polyester resins (UPR) and four different reference UPR products (before and after UVB aging) were analyzed by high-resolution 1D and 2D nuclear magnetic resonance (NMR) spectroscopy. Breaking strain studies were also conducted for the four UPR model products before and after different aging procedures (moisture, UVB exposure, melt/freeze). NMR analysis of the chemical composition of the UPR resin extracts showed they contain several low MW organic compounds and oligomers rich in polar -OH groups that play a significant role in the degradation behavior of the composite UPR materials. Statistical analysis of the NMR compositional data showed that styrene and benzaldehyde contents can be used to differentiate between fresh and aged UPR samples. The phthalate and propylene glycol unit speciation (esterified, primary or secondary -OH) of the extracts provided evidence that UPR resin C was used in the construction of the two art installations, and direct comparison of (1)H and (13)C NMR spectra verified this compositional similarity. UPR resin C was shown by both NMR and breaking strain studies to be the reference UPR most susceptible to degradation by different aging procedures, a characteristic attributed to the lower styrene content of resin C.     

Preparative separation of the flavonoid fractions from Periploca forrestii Schltr. ethanol extracts using macroporous resin combined with HPLC analysis and evaluation of their biological activities

A preparative separation method using macroporous absorptive resin coupled with high‐performance liquid chromatography was developed for the separation of six fractions of the 80% ethanol extract of Periploca forrestii Schltr. The six ethanol fractions (5–95; A, B, C, D, E, and F) obtained were carefully analyzed to locate the corresponding peaks in the high‐performance liquid chromatography chromatogram of the total extract, which was established in a previous study. Furthermore, the biological activities, including antioxidant activities, acetyl cholinesterase inhibitory capacities, antihyaluronidase activities, and anti‐inflammatory effects, were evaluated in MH7A cells. The results demonstrated that fraction E could significantly prevent oxidation and inhibit hyaluronidase and acetyl cholinesterase. Finally, the main flavonoids in fractions A and E from P. forrestii Schltr. were purified, and the compounds were identified as chlorogenic acid, quercetin‐3‐O‐α‐L‐arabinopyranoside, and quercetin‐7‐O‐β‐D‐glucopyranoside. The chemical structures were confirmed by mass spectrometry and nuclear magnetic resonance spectroscopy. Furthermore, the inhibitory effects of these compounds against complete Freund's adjuvant‐induced secondary immune arthritis in rats were evaluated.     

Preparative purification of five bioactive components from Agrimonia pilosa Ledeb by high-speed counter-current chromatography

High-speed counter-current chromatography (HSCCC) coupled with ultraviolet (UV) detection or evaporative light-scattering detection was successfully applied for preparative separation of five bioactive compounds from Agrimonia pilosa Ledeb. In preliminary process, D101 macroporous resin was used to separate the crude extract of the plant and four fractions (20, 40, 50, and 60% aqueous ethanol elutions) were produced. Then, these fractions were directly subjected to HSCCC purification. Five chemicals including taxifolin-3-glucoside (6.4 mg), quercetin-3-rhamnoside (13.0 mg), tiliroside (14.7 mg), agrimonolide (21.4 mg), and tormentic acid (29.8 mg) with the purities of 94.24, 95.37, 97.42, 95.29, and 96.34% were separated from each 200 mg prepared fraction. The purities were analyzed by high-performance liquid chromatography, and the chemical structures of the products were identified by UV detection, mass spectrometry, nuclear magnetic resonance, and the standards. This paper used a simple method to separate five bioactive compounds from A. pilosa Ledeb, and it could provide a new idea for the purification of bioactive compounds from other medicinal plants.     

Flame‐retardant epoxy resin compounds containing novolac derivatives with aromatic compounds

New flame‐retardant epoxy resin compounds containing novolac derivatives with specific aromatic compounds have been developed. After crosslinking reactions between epoxy resin and hardener, the epoxy resin compounds formed highly flame‐retardant network structures that were obtained by including biphenylene and phenylene moieties in the main chains of novolac‐type epoxy resin and phenol novolac resin hardener. The high flame retardancy is due mainly to the stable foam layers that form during combustion because of the low elasticity at high temperatures and the high pyrolysis resistance of the compounds. Furthermore, the addition of excess phenol derivative hardener not only facilitates the formation of the foam layers by decreasing the crosslink densities but also reduces the amount of flammable substances generated from the epoxy resin compounds during combustion. The use of a multifunctional epoxy resin containing four glycidyloxy groups in the compounds improved characteristics such as heat resistance and strength at high temperatures, while maintaining excellent flame retardancy. Copyright © 2001 John Wiley & Sons, Ltd.     

The “Fingerprint” of a freshwater microalga Scenedesmus sp. LX1: Visualizing the composition of its soluble algal products

The composition of soluble algal products was visualized by a fingerprint analytical method.     

Isolation and Purification of Highly Polar Antioxidants from Chirita longgangensis by Combination of Macroporous Resin and HSCCC

An efficient and simple method to isolate and purify highly polar antioxidants from the antioxidant active site of Chirita longgangensishas been established. Firstly, the antioxidant active site was enriched with D101 macroporous resin, and then high-speed counter-current chromatography (HSCCC) was used with the two-phase solvent system ethyl acetate–n-butanol–methanol–water (5:0.1:0.5:4.5, v/v) to obtain four antioxidants in one step. They were identified as plantainoside D (28.4 mg), plantainoside B (9.5 mg), calcedarioside B (18.1 mg) and calcedarioside A (16.7 mg) by analysis of electrospray ionization mass spectrometry (ESI-MS) and nuclear magnetic resonance (NMR) spectra. The purities were all above 97 % as determined by HPLC. The inhibiting effects of the crude extracts, enriched fraction and the obtained compounds on superoxide anion radical, hydroxyl radical and hydrogen peroxide were determined by different chemiluminescence (CL) systems. The result shows that all of them have good antioxidant activity. However, the sequence of antioxidant abilities among compounds I–IV was different when assayed by different CL systems (superoxide anion radical, hydroxyl radical, and hydrogen peroxide). This is the first report on preparative isolation and purification of antioxidants from C. longgangensis by HSCCC combined with macroporous resin and their inhibition of free radical-induced luminol chemiluminescence.     

Improved separation of palladium species in biological matrices by using a combination of gel permeation chromatography and isotachophoresis

The binding of palladium to high-molecular-mass compounds in palladium-treated lettuce is investigated as an example for a biological matrix. The total palladium concentration in lettuce leaves is 10.3 ng/g wet weight. After homogenization, high-molecular-mass compounds (> 10 kDa) are isolated by ultrafiltration. For separation of these palladium species a combination of preparative gel permeation chromatography (GPC) and preparative isotachophoresis (ITP) is used. Palladium is determined in separated fractions by using a highly sensitive total reflection X-ray fluorescence (TXRF) method after preconcentration. After GPC separation, four main fractions of palladium species are collected, each containing palladium in ng quantities (3-10 ng). Two of these fractions are further separated by ITP, yielding at least three main peaks per GPC fraction, each containing palladium in the range of 0.3-3 ng. These palladium containing peaks are characterized by high-performance size exclusion chromatography (HPSEC) and capillary isotachophoresis (cITP) in parallel. HPSEC enables the estimation of the molecular mass of six main palladium peaks, covering a molecular mass range of 69-200 kDa. It is also shown that the estimation of molecular mass after separation is more reliable than the respective estimation directly in the first GPC run. However, cITP reveals that each of the separated peaks is still a mixture of at least five different compounds.     

GC-MS analysis of penta- and tetra-cyclic triterpenes from resins of Pistacia species. Part II. Pistacia terebinthus var. Chia

Pistacia species contain oleoresins with bioactive triterpenes. In this study triterpenes, including minor components, were identified and quantified in both neutral and acidic fractions of Pistacia terebinthus var. Chia resin, grown exclusively in Chios island (Greece), collected traditionally, as well as using stimulating agents (liquid collection). It was proved that these two resin samples were composed of several different minor triterpenes, while major constituents were similar but in different proportions. Compounds that differentiated two resin samples of P. lentiscus and P. terebinthus var. Chia, both traditionally collected, were detected, in order to identify the nature of resins present in archaeological materials. In the traditionally collected resin, 37 triterpenes were identified, 12 in the acidic and 25 in the neutral fraction. In the liquid collection resin 10 compounds were identified in the acidic and 23 in the neutral fraction, while 16 compounds were not contained in the traditionally collected resin. The main triterpenes in both resin samples collected traditionally and using stimulating agents were: isomasticadienonic acid (23.6 and 26.3% w[sol ]w of the triterpenic fraction, respectively), 28-norolean-17-en-3-one (16.3 and 17.5% w[sol ]w of the triterpenic fraction, respectively) and masticadienonic acid (5.8 and 6.0% w[sol ]w of the triterpenic fraction). In this study the qualitative and quantitative composition of triterpenes was compared in the Pistacia lentiscus and P. terebinthus var. Chia resin samples collected with the traditional and new liquid techniques, and also triterpenes in resins of P. terebinthus obtained by the traditional technique and using stimulating agents. The aim of the study was also to examine whether the collection technique influenced the triterpenes contained in P. terebinthus var. Chia resin samples.     

Multivariate Screening Analysis of Water-in-Oil Emulsions in High External Electric Fields as Studied by Means of Dielectric Time Domain Spectroscopy

The effect of crude oil resins with various polar characters on the stability of w/o model emulsions containing asphaltenes is investigated using a mixture design. The resins were extracted using an adsorption-desorption technique. One asphaltene fraction and four different resin fractions from one European crude oil were used. The stabilities are measured using time-domain dielectric spectroscopy in high external electric field. It is found that resins with different polar character have different effects on the emulsion stability. At asphaltene/resin ratios of 1 and 5 : 3 the resins in some cases lead to an emulsion stability higher than that of a similar emulsion stabilized by asphaltenes only, while at low asphaltene/resin ratios ( approximately 1 : 3) the emulsion stability is reduced by the resins. The effect on emulsion stability of combining two different resin fractions depended on the resin types combined as well as the relative amount of resins and asphaltenes. Also, an increase in the stability of some of the emulsions containing resins and asphaltenes for a period of 50-300 min after the emulsification was observed. This time-dependence of emulsion stability is attributed to the mobility of resins at the oil-water interface and the slow buildup of a stabilizing interfacial film consisting of resins and asphaltenes. Copyright 2000 Academic Press.