辣椒红色素的提取工艺及稳定性研究

红辣椒中含有纯天然辣椒红色素，研究了辣椒红色素的几种提取方法。用有机溶剂从辣椒中提取红色素，同时对不同温度、不同时间下的色素提取率进行测试，以确定最佳提取条件；研究发现，乙酸乙酯法可以有效地去除辣椒中的辣味，使产品应用于更广泛的领域。本文还研究了辣椒红色素对pH值、光照、温度、金属离子的稳定性。     

微波辐射离子液体中TiO_2/PS-PEMA复合材料的制备及其性能

以钛酸丁酯为前驱物,在离子液体([Bmim]BF_4)中采用微波辐射加热法合成了TiO_2/PS-PEMA复合材料。通过测试复合材料在乙酸乙酯中的吸光度以及对甲基橙溶液的降解率,考察了离子液体用量、微波功率、反应温度和反应时间等因素对复合材料分散性和光催化活性的影响。结果表明,制备TiO_2/PS-PEMA复合材料的最佳条件为:离子液体用量2.0 mL,微波功率700 w,反应温度70℃,反应时间45 min和引发剂过硫酸钾用量0.10 g。制得的复合材料亲油性大大提高,在乙酸乙酯中有较好的分散性,对甲基橙具有较高的光催化降解活性。     

Preparation of an Acid Butanol Standard from Fresh Apples

We have developed a simple method for preparing and verifying suitable standards for the acid butanol assay from a readily available source. Phenolics were extracted from fresh apples with methanol, and sugars were removed from the crude extract by treatment with Amberlite resin before fractionating the proanthocyanidins into ethyl acetate. The ethyl acetate fraction was chromatographed on Toyopearl TSK HW-50F to yield about 50 mg of procyanidin dimer and 35 mg of trimer from 1 kg fresh apple fruit. The purity and identity of the standards was easily confirmed by using ESI-MS. In the acid butanol assay, the pure dimer, trimer and purified Sorghum procyanidin had similar color yields on a mass basis, and produced about three times more color than purified quebracho tannin. This new standard overcomes problems associated with overestimation of tannin due to use of the unreactive quebracho tannin standard. Use of the new standard will enable accurate comparisons of tannin levels between laboratories and will standardize comparisons between species, thus promoting our understanding of the role of condensed tannins in plants.     

微波助离子液体中TiO_2/PEMA复合材料的制备及性能

在离子液体([Bmim]BF_4)中采用微波辐射加热法合成了TiO_2/PEMA复合材料,用XRD、SEM和IR对其进行表征。通过测试复合材料在乙酸乙酯中的吸光度及对甲基橙溶液的降解率,考察离子液体用量、微波功率、反应温度和反应时间等因素对复合材料分散性和光催化活性的影响。结果表明,制备TiO_2/PEMA复合材料的最佳条件:离子液体2.0 mL,钛酸丁酯3.4 mL,甲基丙烯酸乙酯1.0 mL,微波功率600 W,反应温度70℃,反应时间45 min。制备的复合材料亲油性大大提高,在乙酸乙酯中有较好的分散性,该复合材料不需要高温焙烧就具有较高的光催化活性,紫外光照射1.5 h,甲基橙降解率为99.4%。     

乙酸乙酯与乙酸正丙酯的切换式连续生产

作者在对乙酸乙酯、乙酸异丙酯、乙酸正丙酯和乙酸丁酯的现有生产工艺进行分析后,以乙酸乙酯和乙酸正丙酯为研究对象,在以往对两者研究的基础上,提出了乙酸乙酯与乙酸正丙酯切换式连续生产的工艺流程,并且通过模拟计算和小试验证证明,在同样的生产装置上,可以分别连续生产乙酸乙酯和乙酸正丙酯,采用该工艺生产乙酸乙酯能耗低于传统工艺12%,生产乙酸正丙酯比原有工艺可以提高收率2%。     

The mass transport of ethyl acetate in syndiotactic polystyrene

The mass transport of ethyl acetate in syndiotactic polystyrene (sPS) has been studied. Two groups of specimens were prepared using press‐cooling and water‐quenching. The press‐cooled and water‐quenched specimens were identified as crystalline and amorphous structures, respectively, by X‐ray diffraction. The weight gain of ethyl acetate in sPS was monitored at temperatures from 50°C to 70°C. The crystallinity of a press‐cooled specimen prior to solvent sorption was greater than that after solvent sorption. However, solvent‐induced crystallization was observed in the water‐quenched specimen. The transport of ethyl acetate in both press‐cooled and water‐quenched specimens was anomalous and consisted of two stages. Each stage of the sorption curves was well fitted with Harmon's model. Both the diffusion coefficient and velocity component satisfy Arrhenius behavior. For the press‐cooled specimen, fluxes of Case I and Case II transport flow from the outer surface to the center, but for the water‐quenched specimen, the solvent is squeezed out. Pure Case II transport did not appear in the water‐quenched specimen.     

An insight on the weakening of the interlayer bonds in a Cameroonian kaolinite through DMSO intercalation

In this study, intercalation of dimethylsulphoxide (DMSO) in a Cameroonian kaolinite is used to achieve weakening of the interlayer hydrogen bonds, in the perspective of dispersion or even exfoliation of the clay within polymer composite materials. Displacement of intercalated DMSO by ethyl acetate and ammonium acetate is studied in order to simulate the interactions with the polymer matrix. The exfoliation of the kaolinite is well evidenced by X-ray diffraction and SEM observations. The disruption of the interlayer bonds is shown by the displacement of the FT-IR vibration modes of both Al–OH and Si–O functions, and by the decrease of the dehydroxylation temperature recorded by Controlled Rate Thermal Analysis. Complete displacement of DMSO by ethyl acetate is achieved and the crystalline structure is deeply disordered as a result of interlayer bonds weakening. The displacement of DMSO by ammonium acetate leads to a ternary composite of DMSO/ammonium acetate with respective intercalation ratio of 62.4% and 57.7%.     

生物质焦油成分分析及综合利用研究

生物质焦油是生物质热解和气化过程中产生的副产物,其成分非常复杂。实验对贵州省毕节市农机研究所设计的生物质气化炉所产生的生物质焦油进行了研究,选用混合溶剂(乙酸乙酯∶甲醇=5∶1)作萃取剂,采用GC/MS法对萃取物的化学成分进行了分析。结果表明,已定性的41种化合物大多为苯的衍生物,是重要的化工原料。     

单塔连续制备乙酸乙酯工艺研究

采用反应精馏技术,连续合成乙酸乙酯,通过加入带水剂,使反应生成的水完全带出。在选择的实验条件下,塔顶粗酯产品中乙酸乙酯含量达到91％以上,基本不含酸。塔顶粗酯直接用盐液萃取,可获得符合GB3728—91合格品要求的乙酸乙酯产品。     

废EPS改性制备清香型乳液胶粘剂及粘接应用研究

以MAA(甲基丙烯酸)和PVA(聚乙烯醇)为主要原料,以BPO(过氧化苯甲酰)为引发剂,以乙酸乙酯、丙酮和废弃橙皮精油作为废EPS(聚苯乙烯泡沫塑料)的混合溶剂,制备了清香型废EPS改性胶粘剂。研究结果表明:当混合溶剂中V(乙酸乙酯)∶V(废弃橙皮精油)∶V(丙酮)=5∶3∶2时,其对废EPS的溶解力(8.20 g/10 mL)最强;采用正交试验法优选出制备废EPS改性胶粘剂的最佳工艺条件为w(EPS中MAA)=8%、w(EPS中BPO)=3%、反应温度70℃和w(胶液中PVA)=10.0%,此时改性胶粘剂胶接实木单板的剪切强度可达到0.825 MPa,并且其对织物纤维、纸张等胶接性能良好。     

Specific determination of malonaldehyde by N-methyl-2-phenylindole or thiobarbituric acid

Reactivity of a commercially available test kit (LPO-586), based on N-methyl-2-phenylindole, toward aldehydes was characterized and compared with that of thiobarbituric acid (TBA). In hydrochloric acid, LPO-586 produced a violet pigment with malonaldehyde (MA) but not with other tested aldehydes. In methane sulfonic acid, LPO-586 produced the violet pigment with MA and 4-hydroxynonenal (HNE), but not with other tested aldehydes. Pigment formation with MA was not inhibited by other aldehydes, but that with HNE was inhibited by alka-2,4-dienals. TBA produced a red pigment with MA but not with other tested aldehydes in hydrochloric acid or in acetate with ethylenediaminetetraacetic acid (EDTA). Both the LPO-586 test in hydrochloric acid and the TBA test in hydrochloric acid or in acetate with EDTA can be used for specific measurement of MA in oxidized lipid samples.     

Effect of Solvent on Nanoparticle Production of β‐Carotene by a Supercritical Antisolvent Process

Production of micro‐ to nano‐sized particles of β‐carotene was investigated by means of solution‐enhanced dispersion by supercritical fluids (SEDS). β‐Carotene was dissolved in dichloromethane (DCM), N,N‐dimethylformamide (DMF), n‐hexane, or ethyl acetate, and supercritical CO₂ served as an antisolvent. The effects of the organic solvents, operating pressure, and temperature were examined. The morphologies of the particles produced by the SEDS were observed by field emission‐scanning electron microscopy and particle sizes were determined by image analysis. Irregularly shaped microparticles were produced in the system with DCM and DMF solution. Plate‐like microparticles were generated by using n‐hexane solution and irregular nanoparticles by ethyl acetate solution. The optimum operating conditions were found to be ethyl acetate as solvent in a defined pressure and temperature range.     

Thiobarbituric acid reaction of aldehydes and oxidized lipids in glacial acetic acid

Thiobarbituric acid (TBA) reaction of several aldehydes and oxidized lipids in glacial acetic acid was performed. All the samples were freely soluble in the solvent used. Saturated aldehydes produced a stable yellow pigment with an absorption maximum at 455 nm, a red pigment derived from malonaldehyde at 532 nm, and an orange pigment due to dienals at 495 nm. The absorbance maximum was 7–9 per μmol for saturated aldehydes, 27.5 per μmol for malonaldehyde and about 2 per μmol for dienals. Autoxidation of unoxidized lipids increased progressively in glacial acetic acid. When the TBA test was performed under nitrogen, autoxidation of unoxidized lipids was inhibited completely. While saturated aldehydes produced no yellow pigment under nitrogen, oxidized lipids produced a considerable amount of stable yellow pigment. The value for absorbance at 455 nm as a function of autoxidation time paralleled those of peroxide values. The absorbance of most oxidized lipids at 455 nm was higher than at 532 nm. Yellow pigment formation in the TBA test under nitrogen could not be ascribed to free saturated aldehydes but rather to unspecified closely related substances. The stable yellow pigment was found to be an excellent indicator of lipid oxidation.     

Assessment of the dyeing properties of pigments from Monascus purpureus

Monascus purpureus C322 was cultivated on well‐established production media to yield prevailingly red or orange pigment‐rich ethanolic extracts. Once these extracts had been diluted by an overall factor of 50, they were used as such to dye raw wool standard specimens differently premordanted using alum or stannic chloride. Independently of the mordant used, the specimens dyed with the red pigment‐rich extracts showed a pale red colour tending to pink, whereas the specimens dyed with the orange pigment‐rich extracts exhibited a more definite orange colour. By carrying out a few colourfastness standard tests (manual washing at 40 °C, acid and basic perspiration and hot pressing), stannic chloride‐premordanted wool specimens dyed with the red pigment‐rich extracts were found to be less resistant to acid and basic perspiration than their orange counterparts. Since the production of the orange pigment‐rich ethanolic extracts appeared to be more cost‐effective than that of their red counterparts, the former might support the present demand for colorants of natural origin in the textile sector. Copyright © 2005 Society of Chemical Industry     

Extraction of caffeine from natural matter using a bio-renewable agrochemical solvent

This paper reports experimental data on the pressurized liquid extraction of caffeine from green coffee beans and green tea leaves using ethyl lactate (ethyl 2-hydroxy-propanoate). This solvent is a new bio-renewable agrochemical solvent, naturally produced by fermentation from corn derived feedstock, which has been recently considered as a very suitable and environmental benign solvent for food industrial applications.Static extraction assays (one step during 10 min) were carried out in an Accelerated solvent extraction (ASE) system at three different extraction temperatures, namely 100, 150 and 200 °C. Extraction yield and caffeine recovery were determined and compared with those obtained when using other liquid solvents, such as ethyl acetate or ethanol. High recovery of caffeine (≈60%) was found in the extracts produced using ethyl lactate, which demonstrates the potential use of this green solvent for the extraction of caffeine from different vegetable sources.     

防锈漆的研制

以废旧聚苯乙烯为原料，经松香树脂物理化学改性作成膜物质．铁红为颜料，甲苯、二甲苯、乙酸乙酯为混和溶剂．添加增塑剂、防沉淀剂、流平剂、催干剂等多种助剂研制成多功能防锈漆。     

乙醇一步法制备乙酸乙酯的MOS2/C催化剂

开发了一种新的用于乙醇一步制备乙酸乙酯的MoS2/C催化剂,考察了MoS2前驱负载物四硫代钼酸铵(ATTM)的负载量对MoS2/C催化剂催化性能的影响,结果表明ATTM最佳的负载量为20%,此时乙醇转化率达88%,乙酸乙酯选择性为48%,乙酸乙酯和乙醛联合选择性达85%,过高的负载量会导致乙醇转化率和乙酸乙酯选择性的降低;对乙醇一步合成乙酸乙酯反应机理进行的初步研究表明:乙酸乙酯的生成途径为乙醛和乙醇加成脱氢。     

Synthesis of novel energetic compounds. 8. Electrosynthesis of azidodinitromethyl compounds

Azidodinitromethyl compounds represent a new highly energetic class of propellant ingredients. Preparation of these materials was accomplished by means of electroxidative coupling of azide ions to dinitromethyl carbanions. Thus, anodic coupling of sodium azide with ethyl 4,4-dinitrobutyrate produced ethyl 4-azido-4,4-dinitrobutyrate. Similarly, 4-azido-4,4-dinitrobutyl acetate was prepared from 4,4-dinitrobutyl acetate and converted by way of the corresponding alcohol to the nitrate ester, 4-azido-4,4-dinitrobutyl nitrate.     

Crystallization of acetaminophen micro-particle using supercritical carbon dioxide

Fine particles of acetaminophen were produced by Aerosol Solvent Extraction System (ASES). The experiments were conducted to investigate the effects of various temperatures, pressures, solvents, solution concentrations and solution feed volume rates on particle size and morphology. The choice of solvent appears to be very important for getting specific particle shape and size. The result shows that when ethyl acetate is used as a solvent, the irregular and acicular morphology of raw material is recrystallized to be regular and monoclinic. The average particle size of recrystallized acetaminophen from ethyl acetate solution has been measured to be 3–4 Μm, which was about 1/20th of raw acetaminophen in size. The particle size distribution range also became narrow from 82 Μm to 4.9 Μm.     

液相色谱-串联质谱测定印染废水中3种碱性染料

建立了液相色谱-串联质谱法(LC-MS/MS)测定印染废水中碱性橙2、碱性橙21、碱性橙22三种碱性染料的检测方法。采用乙酸乙酯-环己烷混合溶液(体积比1:1)萃取碱性染料,经凝胶渗透色谱净化浓缩,液相色谱-串联质谱仪测定,结果表明:3种碱性染料在5.0~100.0 ng/m L范围内,线性关系良好,相关系数(R~2)大于0.999 6;检出限在2.5~5.0mg/L之间;回收率在88.6%~98.4%之间,相对标准偏差(RSD)在1.3%~2.7%之间。该方法自动化程度高、样品前处理简单、灵敏度高、检出限低、结果准确可靠、回收率和重现性良好,可用于印染废水中三种碱性染料残留量的同时测定。