Extraction of coals with CS2-N-methyl-2-pyrrolidinone mixed solvent at room temperature Effect of coal rank and synergism of the mixed solvent

Coals (from lignite to anthracite) were extracted at room temperature with CS₂-N-methyl-2-pyrrolidinone (MP) mixed solvent (1:1 by volume), which was found to be a very efficient solvent for the extraction of bituminous coals in a previous study. High yields of 30–66% (daf) were obtained for 29 of the 49 bituminous coals (C%76.9–90.6% daf) examined. The anthracite, subbituminous coals and lignites did not give high yields. The results of the characterization of the raw coals, extracts and residues suggest that reactions between the coals and the solvents do not occur to a significant extent during the extraction. The synergistic effect, i.e. the large increase in yield and rate for the mixed solvent compared with those for CS₂ and MP alone has been explained by increasing solubility and diffusibility of the extracts and increasing swelling of the coals, in the mixed solvent. The mixed solvents of CS₂ with quinoline, pyridine and THF gave lower extraction yields than the CS₂-MP mixed solvent.     

微波条件下氯化锌对乙醇抽提神府煤的影响

微波条件下,研究了在乙醇抽提神府煤中加入氯化锌对其结果的影响。采用气相色谱/质谱联用的方法分析了乙醇和乙醇-氯化锌抽提物的组成;利用傅里叶红外光谱技术分析了神府脱矿物质煤、乙醇抽余煤和乙醇-氯化锌抽余煤的结构。分析结果显示:在乙醇溶剂中添加少量的氯化锌,其抽提物的组成发生了改变;乙醇-氯化锌抽余煤与原脱矿物质煤和乙醇抽余煤相比,芳环吸收强度降低,表明在抽提过程中可能伴随着烷基化反应的发生。     

Effect of coal soluble constituents on caking property of coal

Three cokemaking bituminous coals were extracted by the CS₂/NMP mixed solvents with different content of NMP, and the effect of the amount and the component of coal soluble constituents on the caking property of the extracted residues of coals were investigated in this study. The CS₂/NMP mixed solvent (1:1 by volume) was found to give the maximal extraction yields for the three coals, and the fat coal gave the highest extraction yield of 78.6% (daf) corresponding to its highest caking index of 101. It was found that for coking coal, when the extraction yield got to the maximum of 25.3% in the 1:1 by volume of CS₂/NMP mixed solvent, the residue extracted still had caking property with the caking index of 19. This means parts of the caking constituents of coal are un-extractible because of covalent bonding or strong associative cross-links. The soluble components extracted by the CS₂/NMP mixed solvent and their effects on the caking indexes of the residues at a similar extraction yield quite differed depending on the NMP content in the mixed solvent. The coal solubles extracted by the CS₂/NMP mixed solvent with NMP less than 50% contained less light constituents with less of oxygen groups. This may lead to the decrease in the caking indexes for the residues obtained at the similar extraction yields compared to those of the CS₂/NMP mixed solvent with NMP more than 50%.     

呼伦贝尔褐煤溶剂萃取及萃余煤的双氧水氧化产物分析

以CS2、乙醇和丙酮作为溶剂,对呼伦贝尔褐煤进行连续萃取,并利用气相色谱/质谱联用(GC/MS)技术对萃取物进行分析。结果表明:CS2萃取物主要由长链脂肪烃和芳烃组成,而这些脂肪烃存在于3种溶剂萃取物中。在40℃条件下,用H2O2溶液采用恒温水浴和超声两种方式氧化萃余煤,超声条件下氧化剧烈,并用FTIR分析了原煤、萃余煤、氧化煤的化学结构的变化。氧化后的水溶物用乙酸乙酯萃取后,用GC/MS检测萃取物,恒温水浴氧化可以检测到30种化合物,而超声氧化只检测到14种,且都是以酯类为主。     

两种贵州煤苯-甲醇萃取物族组成分析与萃取动力学探讨

利用苯-甲醇混合溶剂对贵州月亮田和六枝2种煤样进行了索氏萃取,并用柱色谱对萃取物进行了族组分分离。利用GC／MS分析研究了萃取物的族组成,并对萃取动力学特征进行了探讨。实验结果表明:萃取过程阶段性明显,萃取物中烷烃和芳烃含量较高;六枝煤中含有多种含氮和含硫的杂环化合物。     

薰衣草油提取和切割方法的研究

以正己烷、丙酮为溶剂,分别采用溶剂萃取法和水蒸气蒸馏提取薰衣草油,通过GC/MS定性分析提取物组成。结果表明,溶剂萃取法的收率是水蒸气蒸馏的 5倍以上,且萃取物中乙酸芳樟酯含量高于后者,峰面积百分比达到 20%以上,但杂峰数量多;相对来说,丙酮提取物中的低沸点组分偏多,正己烷提取物中的高沸点组分偏多。水蒸气蒸馏提取物中芳樟醇的峰面积百分比达到 34%,樟脑的峰面积百分比超过 5%,均明显高于溶剂萃取。针对正辛烷 /正庚烷 /异戊醇模拟体系的水蒸气蒸馏实验表明,水蒸气蒸馏能优先提取混合物中低沸点、强极性组分,可用于薰衣草油的精制和切割。     

童亭煤族组分的溶剂萃取及萃取物分析

采用正己烷、甲醇、丙酮和氯仿4种溶剂对童亭煤经CS2/NMP混合溶剂萃取和反萃取所分离的3个族组分(沥青质组分、精煤和萃余煤组分)进行索氏分级分次萃取,以FTIR和GC为分析测试手段,研究各组分萃取物的结构特征和其中小分子的赋存规律。结果表明:各族组分在不同溶剂中溶解能力差异显著,沥青质组分在正己烷中有很高的萃取率,而精煤则在丙酮中有大量物质被溶出,萃余煤在氯仿中表现出较高的可溶性;各族组分可溶物在溶出行为和组成结构上既有相似性又存在一定的差别;各族组分可溶物中均有小分子化合物存在,且这些GC可检测的小分子主要集中于一定的保留时间区域内;不同族组分中的小分子的赋存形态具有相似性,且这种赋存形态是影响小分子溶出行为的决定性因素。     

Chemical Analysis of Polyphenols with Antioxidant Capacity from Pinus durangensis Bark

The most active phenolics in Pinus durangensis residual bark were identified and evaluated following a chromatographic fractionation. Bark powder was defatted with hexane, and a crude extract (CE) was obtained by extraction with aqueous acetone (67%). A liquid partition with ethyl acetate was performed to produce an organic extract (OE), which was subsequently purified by column chromatography (Toyopearl HW-40F, methanol), resulting in ten fractions (MF1 to MF10) and an oligomeric fraction eluted with acetone 67% (OLF). Subfraction MF6-1 was obtained by a second chromatographic purification of MF6. Extraction yields, total phenolics, flavonoids, and flavanols contents were determined in CE and OE. The antioxidant activity of bark extracts was measured by DPPH and ABTS assays at 100 µg/mL, expressed in percentage, median effective concentration (IC₅₀), and TEAC (mM). Also the low density lipoprotein inhibition was evaluated. Identification of major phenolics was carried out by HPLCESI–MS and HPLC–DAD instruments. Bioactive taxifolin (dihydroquercetin), dihydromyricetin, myricetin, quercetin, pinomyricetin (myricetin-methoxy), pinoquercetin (quercetin-methoxy), trimeric, and tetrameric procyanidins were detected and identified in P. durangensis bark extracts. Polyphenols found are similar to those contained in Pycnogenol and other Pinus species.     

乙醇提取-丙酮沉淀法提取分离茶皂素的工艺研究

以油茶饼粕为原料,采用乙醇提取-丙酮沉淀法对茶皂素进行提取分离。以茶皂素纯度和得率为考察指标,对乙醇体积分数、液料比、提取温度、提取时间、提取次数、提取液浓缩程度和丙酮用量等工艺参数进行了单因素优化。结果表明：体积分数95%的乙醇为提取溶剂,乙醇与预处理过的油茶饼粕液料比为9：1（mL：g）,提取温度为70℃,提取时间为4 h,提取次数为2次,提取液浓缩至刚好有固体析出,丙酮用量为4倍浓缩液体积量时提取分离效果较佳,得到的茶皂素纯度为85.17%,得率为9.82%。不同溶剂打浆对产品纯化效果的比较发现：丙酮、乙酸乙酯、无水乙醇、体积分数95%的乙醇作为打浆纯化溶剂用于提高茶皂素纯度效果均不明显。     

Antioxidant activity of extracts of defatted seeds of niger (<Emphasis Type="Italic">Guizotia abyssinica</Emphasis>)

Niger (Guizotia abyssinica) seed was ground and then defatted with hexane. The meal remaining after oil extraction was tested as a source of antioxidants. Three solvent systems, A [80∶20 (vol/vol) ethanol/water], B [80∶20 (vol/vol) acetone/water], and C (water) were evaluated as extraction media. Crude extracts were examined for their antioxidant activity in a β-carotene-linoleate and a meat model system. Extract A exhibited superior antioxidant activity, compared to extracts B and C, and its composition was studied further by using column chromatography and HPLC. Four fractions (I–IV) were obtained, of which fractions III and IV showed activity in the β-carotene-linoleate model system. Fraction IV was also highly effective in scavenging the 2,2-diphenyl-1-picrylhydrazyl radical but was less active when used in a bulk oil model system. Preparative TLC showed fraction IV as consisting of two components. UV spectroscopy suggested that the major active component pressent was a chlorogenic acid-related compound. Furthermore, HPLC analysis established that chlorogenic acid was dominant in the free phenolics fraction (2.6 mg/g). Upon hydrolysis, however, a substantial amount of caffeic acid (42.8 mg/g) was released, presumably from esterified and glycosylated chlorogenic acid. Thus, niger extracts derive their antioxidant activity, at least in part, from the chlorogenic acid-related compounds.     

烟煤和褐煤分级萃取物的GC/MS分析

采用乙醇、丙酮、离子液体/N-甲基吡咯烷酮(ILs/NMP)和在微波辅助下ILs/NMP分别对宁夏双马烟煤(SM)、宁夏鸳鸯湖烟煤(YYH)、云南莲花塘褐煤(LHT)、内蒙古通辽褐煤(TL)进行分级萃取,依次得到了萃取物(E 1~E 4)和萃余煤(R 1~R 4)。利用气相色谱质谱联用(GC/MS)对E 1~E 4进行分析,傅立叶变换红外光谱(FT-IR)对R 1~R 4进行分析。结果表明:经乙醇、丙酮分级萃取之后,不同种类的亲水型离子液体对同一种煤的萃取率不同,亲水型离子液体与疏水型离子液体对同一种煤的萃取效果也不同,疏水型离子液体的萃取率更高。[Bmim]NTf 2/NMP的可检测化合物中发现酰胺类化合物,[Bmim]Cl/NMP的可检测化合物没有发现酰胺类化合物。分级萃取的萃余煤(R 1~R 4)中脂肪族化合物,芳香族化合物及含氮化合物的含量逐级减少,相应地,它们在萃取液中含量增大。微波辅助下,离子液体的加入可使煤中强键断裂,使萃取液中含氮化合物的种类明显增加。     

用LC/APCI/MS方法检测粉尘中的炸药成分

采用高选择性和灵敏度的LC(液相色谱)/APCI(大气压化学电离源)/MS(质谱)方法定量分析粉尘样品中的HMX、RDX、PETN、CE、NQ和TNT。采用ASE萃取,GPC净化浓缩作为前处理方法,在粉尘中分别添加所测炸药组分,用丙酮作为ASE萃取溶剂,乙酸乙酯和环己烷(体积比为1∶1)作为GPC净化时的流动相并抛弃杂质500s,收集1 520s。在LC/MS分析时,通过在流动相中添加1mmol/L甲酸与样品形成[M+HCOO]-的甲酸加合离子。结果表明,HMX、RDX、PETN、CE、NQ、TNT的方法检测限分别为0.78,1.44,1.69,0.77,1.06,1.72ng/mL,回收率为49.0%～88.4%,相对标准偏差为3.5%～10.3%。该方法可以用来系统排查及定量分析爆炸残留物及环境样品中的NQ、RDX、PETN、CE、HMX、TNT成分。     

Average structure of extracts of a butylated coking coal

A high-vitrinite coking coal (87%C, daf) was subjected to reductive and non-reductive butylation and the yields of their chloroform extracts (butylated coal basis) were 67.2 and 17.1 wt% respectively. The extracts were separated by adsorption and gel permeation chromatography into a few fractions so that the latter were in ‘equimolar’ ratios (considering the average molecular masses). The soluble fractions were characterized by elemental and average molecular mass analysis and data derived from ¹H and ¹³C n.m.r. spectra and average structural models of the fractions were constructed.     

Determination of free gossypol in chemically treated cottonseed meals containing dianilinogossypol

Summary A method is proposed for the determination of free gossypol in chemically treated cottonseed meals containing dianilinogossypol. The procedure includes a rapid qualitative test for detecting the presence of dianilinogossypol in cottonseed meals. Investigation of the properties of dianilinogossypol showed that it was appreciably soluble in water-free solvents, such as acetone, methyl ethyl ketone, or chloroform, but only slightly soluble in 70% acetone, an efficient solvent for the extraction of free gossypol. Both 70% acetone extracts of chemically treated meals and pure dianilinogossypol in the same solvent exhibited significant changes in optical density due to slow hydrolysis of dianilinogossypol. Dilution of aqueous acetone extracts with 80% isopropyl alcohol produced changes in optical density even greater than those occurring in undiluted extracts, introducing serious errors in the free gossypol determination. The addition of a small amount of aniline to the aqueous acetone for extraction stabilized the extract against changes in optical density and yielded constant values for free gossypol over a period of several hours. Use of aqueous acetone without aniline gave values which increased with the time interval between extraction and analysis. Extrapolation of these values to zero time gave results in good agreement with those obtained by the use of aqueous acetone containing aniline. The intense background color in extracts of chemically treated meals introduces a source of error when photoelectric colorimeters yielding non-linear calibration curves are used for analysis. A modification in the customary method of calculation eliminates this source of error. One of the laboratories of the Southern Utilization Research Branch, Agricultural Research Service, U. S. Department of Agriculture.     

混合溶剂提取催吐萝芙木水溶性生物碱的工艺研究

用混合溶剂提取法研究催吐萝芙木水溶性生物碱的浸提工艺。考察了不同混合溶剂对水溶性生物碱提取率的影响,确定了丙酮-水（v：v=10：1）混合溶剂为适宜溶媒,并通过正交实验,确立了该溶媒提取催吐萝芙木水溶性生物碱的优化条件：8倍量的混合溶剂,提取时间10h,温度40℃,pH=10。在优化后的条件下,采用该混合溶剂对水溶性生物碱提取率为3．22％,是采用乙醇的1．35倍,蒸馏水的1．69倍。     

Separation,Identification, Antioxidant,and Anti-Tumor Activities of Hibiscus sabdariffa L. Extracts

Roselle (Hibiscus sabdariffa L.) belongs to the malvaceae family. Its calyx is used for making jellies, jams, and beverages. Despite it usefulness, there are few or no studies on the purification and structural identification of HAs and Roselle extracts. This paper therefore seeks to investigate the purification and structural identification of Hibiscus sabdariffa L. extracts, and to evaluate their antioxidant activities on DPPH and ABTS and anti-tumor activities on human cervical cancer HeLa cells of purified fractions. Two fractions (fraction 1 and fraction 2) from Roselle (Hibiscus sabdariffa L.) extracts were purified with C-18 Sep-Pak cartridge, followed by Sephadex LH-20 column and characterized by HPLC-ESI-MS/MS. The contents of the anthocyanins in fraction 1 and fraction 2 were 863.41 mg/g and 617.35 mg/g, respectively. Nine compounds were identified with HPLC-ESI-MS/MS, seven of which have not been reported before in Roselle. Two fractions and HAs-rich extracts purified with C-18 Sep-Pak cartridge showed high capacity on radicals scavenging and HeLa cells inhibition in a dose-dependent manner. The orders of both activities were: fraction 1 > fraction 2 > HAs-rich extracts. IC₅₀ values of fraction 1 on DPPH and ABTS radicals were 17.14 ± 2.24 μg/mL and 85.91 ± 6.72 μg/mL, respectively. The cell inhibition ratio of fraction 1 against HeLa cells reached 83.67 ± 3.07% at the concentration of 200 μg/mL. Two fractions and HAs-rich extracts could be a good supplements for natural antioxidant and anti-tumor activities.     

Sterols in chloroplasts: A description of two qualitatively distinct forms

Chloroplasts from eight plant species have been extracted sequentially with petroleum ether (PE) and acetone (A) and the extracts analyzed for sterols. Cholesterol was a component of all fractions analyzed but it was found that the A fraction of each species contained relatively much more cholesterol than the PE fraction. Other components of the PE sterol fractions were plant sterols typical of the species examined and were quantitatively markedly different from those in the corresponding A fractions. The yield of sterol from chloroplasts was found to be 0.02–0.03% and the ratio of the PE/A fractions to be 5∶1–19∶1.     

花椒总多酚的超声提取与分离研究

以湘西青花椒为原料,采用超声辅助萃取法提取总多酚,用单因素实验和正交试验考查了丙酮体积分数,料液比,提取温度和提取时间对花椒总多酚提取率的影响.结果表明:以40%丙酮为溶剂,在料液比为1:15(m/V)、60℃温度下超声提取80 min,总多酚提取率为0.5068%.     

Effect of solvent (CO2/ethanol/H2O) on the fractionated enhanced solvent extraction of anthocyanins from elderberry pomace

The management of agro-industrial residues is an important issue for environmental reasons and the reuse of byproducts represents a good alternative, especially if it is conjugated with green technologies and the production of valuable products. Portuguese elderberry pomace is rich in anthocyanins with therapeutic properties that confer to this byproduct potential to be applied in the food and pharmaceutical industries. Fractionated high pressure extractions from elderberry pomace were performed using supercritical CO₂ extraction, followed by enhanced solvent extraction (ESE) with diverse CO₂/ethanol/H₂O solvent mixtures (0-90%, 0.5-100%, 0-95%, v/v/v), at 313 K and 21 MPa, in order to obtain anthocyanin-rich fractions. The ESE solvent mixtures had a substantial effect on extracts yield and composition. The maximum extraction yield (24.2%), total phenolic compounds (15.8% gallic acid equivalents), total flavonoids (8.9% epicatechin equivalents), total anthocyanins (15.0% cyanidin-3-glucoside equivalents) and antioxidant activity (IC₅₀ of 21 μg) achieved highlight the great potential of elderberry pomace for valuable applications.     

Preparation,morphology, and mechanical properties of elastomers based on α,ω‐dihydroxy‐polydimethylsiloxane/polystyrene blends

α,ω‐Dihydroxy‐polydimethylsiloxane/polystyrene (PDMS/PS) blends were prepared by the solution polymerization of styrene (St) in the presence of α,ω ‐dihydroxy‐polydimethylsiloxane (PDMS), using toluene as solvent and benzoyl peroxide (BPO) as initiator. The PDMS/PS blends obtained by this method are a series of stable, white gums, which were vulcanized to elastomers at room temperature with methyl‐triethoxysilicane (MTES). The use level of MTES was far more than the necessary amount used to end‐link hydroxy‐terminated chains of PDMS, with the excess being hydrolyzed to crosslinked networks, which were similar to SiO₂ and acted as filler. Investigations were carried out on the elastomeric materials by extraction measurement, swelling measurement, and scanning electron microscopy. The extraction data show that at each composition the amount of soluble fraction is less than expected and the difference between experimental and theoretical values becomes more and more significant as PS content increases. This is mainly due to the grafting of PS onto PDMS and the entanglement of PS in the interpenetrating polymer network (IPN), which consists of either directly linked PDMS chains or chains linked via PS grafts and is formed by free radical crosslinking of PDMS during the radical polymerization of St. PS grafted on PDMS is insoluble and PS entangled in the IPN is difficult to extract. Both render the soluble fraction to be less than expected. As the St content in preparing PDMS/PS blends increases, the probability of grafting PS onto PDMS also increases, which may subsequently produce a higher crosslinking level of PDMS networks that linked via PS grafts by radical crosslinking. As a result, not only the amount of insoluble PS increases but also PS entangled in the IPN is more difficult to extract. Scanning electron microscopy demonstrates that the elastomer system has a microphase‐separated structure and a certain amount of PS remains in the PDMS networks after extraction, which is in accordance with the extraction data. Moreover, the mechanical properties of the elastormeric materials have been studied in detail. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3542–3548, 2004