蒸馏温度对核桃壳生物油馏分组分分布的影响

通过改变蒸馏温度对生物油进行常压蒸馏并将馏分分为油水两相，研究了馏分的组分分布变化。结果表明，在120-300℃随着蒸馏温度的升高，生物油馏出率不断增加；蒸馏温度低于240℃的油相馏分中萘、甲苯等芳烃类化合物和乙酸等羧酸类化合物明显富集，以120℃油相馏分为例，芳烃类和羧酸类化合物的相对含量是生物油原油的13.86倍和3.15倍；当蒸馏温度高于240℃时苯酚、愈创木酚等酚类化合物大量馏出，使得油相馏分的产率明显增加；同时，所获水相馏分中的水分含量皆高于60%，水分的富集效果明显；在馏分中检测到了2-乙基乙酸丁酯和环戊酮等原油中未检测到的组分并且馏分中水分总量高于生物油原油，这些都表明生物油在蒸馏过程中发生了酯化、缩聚等化学反应。通过对油相馏分的组分分布进行分析，发现改变蒸馏温度可以有效富集生物油中的高价值化合物，如苯酚、愈创木酚、4-甲基愈创木酚、4-乙基愈创木酚和4-丙基愈创木酚的相对含量在300℃的油相馏分中分别比生物油提高了109%、160%、84%、53%和444%。     

Ba2+沉淀法提取生物油馏分中的酚类物质

从NaOH试剂浓度、反应温度与反应时间三个方面,对钡离子沉淀法提取不同温度段收集的生物油馏分中的酚类物质进行了实验研究,并利用气相色谱-质谱联用仪（GC-MS）对提取效果进行了分析。实验结果表明,钡离子沉淀法对愈创木酚类物质的提取效果较为突出,且NaOH浓度（1.0-6.0mol/L）、反应温度（30-50℃）与反应时间（10-40min）对愈创木酚的提取率影响较大。在NaOH浓度为5.5mol/L、反应温度为35℃、反应时间为20min时,提取率达到最大,其中,三个温度段收集的生物油即低温水相馏分、低温油相馏分与高温馏分中的愈创木酚提取率分别为34.1%、33.8%和33.5%。     

生物油酸性组分分离精制研究

生物油因水分含量高和呈酸性未能作为高品位能源直接规模化应用。利用分子蒸馏技术将生物油水分与酸性组分作为整体对象进行分离,既得到生物油酸性组分富集馏分,又获得了水分含量低、酸性较弱与热值较高的精制生物油Ⅰ（蒸馏重质馏分）与精制生物油Ⅱ（常温冷凝馏分）。同时,具体考察了精制前后生物油的pH值、热值和水分等参数的变化规律。研究表明,生物油的水分与酸性组分得到有效分离,精制生物油Ⅰ和Ⅱ的低级羧酸含量从原始生物油的18.85%分别降低至0.96%和2.2%     

气相色谱-质谱法测定玩具中的9种有机物残留量

建立了气相色谱-质谱测定塑料玩具中乙二醇单乙醚、2-甲氧基乙酸乙酯、苯乙烯、2-乙氧基乙酸乙酯、环己酮、双(2-甲氧基乙基)醚、三甲苯、硝基苯、异佛尔酮9种有机物残留量的方法.不同材质的塑料玩具样品经相应溶剂提取,离心后的澄清溶液经Envi-carb石墨化碳固相萃取小柱净化,旋蒸、氮吹浓缩,甲醇定容,过0.2 μm滤膜...     

高温煤焦油的超临界萃取分馏研究

采用正戊烷溶剂,在超临界状态下,于220℃和5MPa~15MPa循序升压条件下,将高温煤焦油萃取分馏为10个液相窄馏分和1个固相沥青产物;切割深度达78.36%,萃余沥青收率为21.64%,明显低于常规蒸馏沥青收率。研究发现,所用高温煤焦油的初馏分萃取收率最高,随着萃取压力的增加,较低压力段一次萃取液相馏分的收率迅速减少;压力达到10 MPa,液相馏分总收率趋于峰值。元素分析和色质联用分析数据表明,随着萃取压力的增加,一次萃取获得窄馏分的碳氢原子比逐渐增加,平均环数和相对分子质量均逐渐增大,萃取馏分逐渐变重。     

中国桦甸油页岩超临界萃取研究

对桦甸北台子油页岩样品,用甲苯、甲苯四氢萘混合溶剂进行丁非等温(升温速率为8 K·min~(-1))的超临界萃取实验(萃取压力为10MPa,终温为550℃)。为选择高转化率和油类产物高产率的萃取条件,进行了样品粒度(1.2—2.5mm)、溶剂流率(2dm~3·h~(-1))以及甲苯中供氢组分含量(分别为10%、20%、30%)的系统实验。甲苯溶剂超临界萃取油类产物产率是一般干馏方法的2倍。在溶剂甲苯中加入少量供氢组分后,油母转化完全,油类产物产率高。超临界萃取可用一级反应描述,文中用积分法求解了动力学参数。     

柠檬桉叶挥发性成分的提取及成分分析

采用水蒸气蒸馏法从柠檬桉叶中提取挥发油中的油相成分,用乙醚作为溶剂从蒸馏残液中萃取挥发油中的水溶性物质,利用气相色谱-质谱联用(GC-MS)分析二者的化学成分并进行比较。柠檬桉叶挥发油油相成分的得油率为1.36%(以鲜重计),确认了其中的37种成分,占油相成分总量的97.36%,其中有12种碳氢化合物和25种含氧化合物,其主要成分为香茅醛(57.00%),其后依次是香茅醇(15.89%)、乙酸香茅酯(15.33%)。水溶性成分的得油率为0.48%(以鲜重计),确认了其中的10种成分,占水溶性物质总量的82.05%,主要为醇类物质,其主要成分为顺-对烷-3,8-二醇(53.43%)和反-对烷-3,8-二醇(16.48%)。     

固相微萃取法测定负压体系中的微量挥发性有机物

通过固相微萃取气相色谱质谱法定性或定量检测负压体系中十二种微量挥发性有机物,如乙醇、二氯甲烷、乙酸乙酯、正己烷、甲苯等,检出范围1.6 ×l0-3 μg.L-1 ～1.7 μg.L-1.     

超声波萃取与索氏萃取丙烯腈-丁二烯-苯乙烯中四溴双酚A的比较研究

采用气相色谱-质谱法对超声波萃取与索氏萃取丙烯腈-丁二烯-苯乙烯(ABS)中四溴双酚A进行了比较研究。超声波萃取的最优试验条件:溶剂为二氯甲烷,温度为30℃,时间为60min;索氏萃取的最优试验条件:溶剂为甲苯,回流次数为每小时4次,时间为12h。四溴双酚A的质量浓度在1.00~100mg·L-1范围内与其峰面积呈线性关系。索氏萃取的萃取率高于超声波萃取的萃取率,索氏萃取的相对标准偏差(n=6)为2.1%,加标回收率在80.4%~85.7%之间。     

淖毛湖煤热解重油直接转化制备芳烃化合物研究

采用实沸点蒸馏对新疆淖毛湖煤热解焦油进行了馏分分离,对其中 320℃重质馏分进行四组分分析可以发现,胶质含量28.84%,沥青质含量35.12%,属于加氢中很难以转化的组分;13C-NMR结果显示,重油中芳香碳相对摩尔占比71.16%,说明重质馏分中芳香族化合物占主体地位。采用悬浮床+固定床联合裂化工艺处理重质馏分,并对产物油进行分析,结果显示,沥青质胶质等几乎完全转化,180℃石脑油收率66.95%, 180℃柴油馏分收率17.84%,硫、氮、氧等杂原子得到深度脱除。对180℃石脑油进行催化重整,环烷烃减少了60.23%,芳香烃增加了65.8%,说明重整过程中主要发生了环烷烃脱氢芳化反应,正构烷烃减少了13.42%,说明同时伴有正构烷烃异构化和环化反应。催化重整产物油中苯、甲苯、二甲苯及乙苯的含量较多,分别为11.97%、23.15%、21.43%、3.48%。煤热解重油直接转化过程中煤基本结构单元的传递性得到了显著的体现。     

烯丙基硅烷的一步法合成研究

采用一步合成方式,将3-溴丙烯与金属镁在以甲苯和供电子溶剂(乙醚或THF)构成的混合溶剂中进行反应,继而与四氯化硅反应,成功合成了四烯丙基硅烷,其产率在乙醚与3-溴丙烯的摩尔比为4(V甲苯/V乙醚=1·1)时达到极值,超过了91%。研究同时发现,选择THF代替乙醚时,同样在THF与3-溴丙烯的摩尔比为4(V甲苯/VTHF=1·7)时产率达到极值(63·12%)。本过程可提高产率,降低成本,是一条好的生产四烯丙基硅烷的路线。     

Identification of volatile components in yak butter using SAFE, SDE and HS-SPME-GC/MS

The volatile components of yak butter were isolated by solvent-assisted flavour evaporation (SAFE), simultaneous distillation extraction (SDE; dichloromethane and diethyl ether as solvent, respectively) and headspace solid-phase microextraction (HS-SPME; CAR/PDMS, PDMS/DVB and DVB/CAR/PDMS fibre extraction, respectively) and were analysed by GC/MS. A total of 83 volatile components were identified under six different conditions, including 28 acids, 12 esters, 11 ketones, 10 lactones, 10 alcohols, 4 other compounds, 2 aldehydes, 2 unsaturated aldehydes, 1 furan, 1 sulphur-containing compound, 1 unsaturated alcohol and 1 unsatruated ketone. Among them, 51 were identified by SAFE, 58 by SDE (45 with dichloromethane as solvent and 41 with diethyl ether as solvent) and 40 by HS-SPME (26 with CAR/PDMS; 26 with PDMS/DVB and 32 with DVB/CAR/PDMS). Three pretreatment methods were compared to show that the volatile components obtained using different methods varied greatly, both in terms of categories and in content. Therefore, a multi-pretreatment method should be adopted, together with GC/MS. A total of 25 aroma-active compounds were detected by gas chromatography-olfactometry, among which 20 aroma-active compounds were found by SDE (14 with dichloromethane as solvent and 14 with diethyl ether as solvent) and 17 by SAFE.     

不同蒸馏压力下的生物油分子蒸馏分离特性研究

采用分子蒸馏分离技术对热敏性生物油在不同蒸馏压力下的分离特性进行了研究。经过分子蒸馏分离后,生物油被分离为蒸出馏分油与残留馏分油,蒸出馏分油的得率随着压力的下降而显著增大,在700 Pa时达到了56.50%(质量分数)。在馏分油的物理性质方面,蒸出馏分油富集了生物油内的大部分水分,残留馏分油内水分得到了较好的脱除,其中,700 Pa下残留馏分油的水分含量降至4.20%(质量分数)。结合生物油及馏分油的GC-MS分析结果,对乙酸、苯酚、糠醛以及左旋葡聚糖等生物油内典型化合物在不同蒸馏压力下的分布特性进行了研究,获得了相应化合物在分子蒸馏过程中的富集规律。结合分离因子评估模型对生物油内14种代表化合物的富集特性进行了量化评价。     

Remarks on the detection of phenols in airborne particulate matter

Summary Samples of suspended particulate matter collected in Duisburg were investigated for phenolic compounds. The loaded filters were extracted with dichloromethane for 10 hours in a soxhlet apparatus. The concentrated extract was resolved in cyclohexane and separated into a non polar and a polar fraction on alumina. The polar fraction was taken up in dichloromethane and steam-distilled. The distillate was extracted with ether. After the evaporation of the ether, the residue was resolved in dichloromethane and allowed to react with benzoyl chloride. After adding toluene the solution was reduced in volume and analyzed in a GC-MS system. For the separation of phenols by means of HPLC the enrichment of the phenols was performed without benzoylization. Six phenols were detected: hydroxibenzene, methylhydroxibenzene, hydroxibiphenyl, hydroxifluorene, benzylhydroxibenzene and dihydroxibiphenyl.     

三裂叶豚草花序挥发成分的GC-MS分析

三裂叶豚草（ＡｍｂｒｏｓｉａｔｒｉｆｉｄａＬ．）为３０年代传入我国的危险杂草,近年来在东北地区有蔓延的趋势。豚草花粉是人类枯草热症的主要致敏源。该文首次对三裂叶豚草花序的挥发成分进行定性、定量分析。新鲜花序以水蒸汽蒸馏法提取,应用ＧＣ－ＭＳ方法,鉴定出４１种化合物,为探讨豚草对人类致病机理与植物受害机制提供依据。     

Production and separation of phenols from biomass-derived bio-petroleum

Cotton stalk was directly deoxy-liquefied in the air-proof stainless steel reactor heated at the rate of 10 °C/min to the final temperature of 450 °C. The bio-petroleum was analyzed by using FTIR and GC–MS, which showed that bio-petroleum had low oxygen content, high H/C molar ratio and heating values, as well as the especially high content of phenols (relative content: 55.21%). The bio-petroleum was rectified under vacuum, and the distillate of 180–260 °C with phenols (relative content: 78.84%) was obtained by controlling the boiling point. The phenols were further recovered by mixing with sodium hydroxide solution and hydrochloric acid, followed by the extraction with dichloromethane. The dichloromethane layer was separated and distilled under vacuum with the protection of nitrogen. Thus, the high-purity phenol derivatives, such as phenol, cresols, guaiacol, 4-methyl guaiacol and syringol were obtained. The results indicated that the extraction by organic solvents was effective in separating and purifying phenols from bio-petroleum.     

神华煤直接液化残渣超临界溶剂萃取研究

利用甲苯、苯和乙醇三种溶剂在反应釜中对神华煤直接液化残渣进行了超临界溶剂萃取,考察了压力、温度、萃取时间、溶剂/残渣比等对萃取产物收率和重质液体萃取组成的影响。结果表明,以甲苯为溶剂进行萃取时,萃取时间对重质液体产率及HS和A收率的影响不大,而温度、压力以及溶剂/残渣质量比都会影响萃取产物的产率及组成。溶剂超临界萃取过程中,有其他组分向HS组分转化,提高了HS的收率。三种溶剂中,苯显示了和甲苯相似的萃取性能,而乙醇的萃取性能相比苯和甲苯则较差,但乙醇萃取得到的重质液体中轻质组分含量高于苯和甲苯。萃取过程中,残渣中的灰分和硫分主要富集至萃取残渣中。     

Chlorobiphenyls in sewage sludge; comparison of extraction methods

Six extraction methods for the analysis of PCBs (CB-28, CB-52, CB-101, CB-118, CB-138, CB-153 and CB-180) in sewage sludge were tested. A certified reference material (CRM 392) was used for the evaluation of the performance of the methods. Soxhlet-Dean-Starch with toluene as solvent, Soxhlet with hexane:acetone (2:3), cold digestion/saponification with 2 mol/L KOH in methanol followed by partition with hexane, and sonicated liquid-solid extraction with hexane:acetone (1:1) produced accurate results (97%, 93%, 104%, and 88%, respectively) with acceptable precisions (6.2%, 6.8%, 15% and 12%, respectively). Results in close agreement with the certified value for all congeners were obtained by treatment with BF₃-methanol prior to partition with dichloromethane. However, this is a tedious procedure and involves the use of hazardous compounds. Cyclic steam distillation produced results with an accuracy of around 80% and a good precision (5.2%). The very low consumption of solvents and other expensive chemicals by this technique and the possibility of analyzing the extract directly without clean-up make it an interesting alternative to the more sophisticated methods. Column elution with dichloromethane was found to be less efficient (61%), but it is a rapid, direct method with a low consumption of solvents and it may therefore serve as screening method. Received: 29 April 1997 / Revised: 30 July 1997 / Accepted: 6 August 1997     

Chlorobiphenyls in sewage sludge; comparison of extraction methods

Six extraction methods for the analysis of PCBs (CB-28, CB-52, CB-101, CB-118, CB-138, CB-153 and CB-180) in sewage sludge were tested. A certified reference material (CRM 392) was used for the evaluation of the performance of the methods. Soxhlet-Dean-Starch with toluene as solvent, Soxhlet with hexane:acetone (2:3), cold digestion/saponification with 2 mol/L KOH in methanol followed by partition with hexane, and sonicated liquid-solid extraction with hexane:acetone (1:1) produced accurate results (97%, 93%, 104%, and 88%, respectively) with acceptable precisions (6.2%, 6.8%, 15% and 12%, respectively). Results in close agreement with the certified value for all congeners were obtained by treatment with BF₃-methanol prior to partition with dichloromethane. However, this is a tedious procedure and involves the use of hazardous compounds. Cyclic steam distillation produced results with an accuracy of around 80% and a good precision (5.2%). The very low consumption of solvents and other expensive chemicals by this technique and the possibility of analyzing the extract directly without clean-up make it an interesting alternative to the more sophisticated methods. Column elution with dichloromethane was found to be less efficient (61%), but it is a rapid, direct method with a low consumption of solvents and it may therefore serve as screening method. Received: 29 April 1997 / Revised: 30 July 1997 / Accepted: 6 August 1997