Studies on Oxygen Characteristics of YBa_2Cu_3O_(7-x) and Its Applications to Air Separation and Gas Purification

Oxygen diffusion and oxygen selective adsorption properties of rare earths material YBa_2Cu_3O_(7-x) (YBCO) were investigated by thermogravimetric, oxygen static adsorption and selectivity adsorption experiments. The results show that YBCO is a very good deoxidizing material. The oxygen desorption of YBCO begins remarkably at about 400 ℃, mass loss can arrive at 1.2% of its original quantity at 800 ℃. Oxygen can be completely absorbed back into the sample again when temperature descends to 400 ℃. The oxygen adsorption selectivity, reproducibility and oxygen adsorption under very low oxygen partial pressure make the material desirable for air separation and gas purification. High purity nitrogen gas was produced with the YBCO molecular sieves in the air separation and gas purification experiments. 0.017 m^3 of high purity nitrogen (>99.9999%) can be obtained with 1 kg YBCO molecular sieve in one cycle. As a deoxidant, an obvious advantage of YBCO is that no hydrogen is needed in its applications.

Separation and purification of deoxynivalenol(DON) mycotoxin from wheat culture using a simple two-step silica gel column chromatography

Deoxynivalenol（DON） is a type B trichothecenes mycotoxin produced by several Fusarium species, often found in foodstuffs for humans and animals. DON is in great demand for the toxicological researches both in vivo and in vitro. In this work, wheat culture was inoculated with a Fusarium graminearum PH-1 strain for DON production. The solvent system for crude extraction was acetonitrile-water（84：16, v/v）. A simple two-step silica gel column chromatography was employed to separate the DON mycotoxin from wheat culture, combined with preparative high performance liquid chromatography（preparative HPLC） to purify the compound. The solvent system for the second silica gel column chromatography was methylene chloride-methanol（17：1, v/v）, which provided a good elution effect selected on thin layer chromatography（TLC）. The target compound was identified by HPLC, and the chemical structure was confirmed by mass spectrometry（MS） and ~1H and ^（13）C nuclear magnetic resonance（NMR） spectroscopy. A total of 433 mg of purified DON was obtained from 1 kg of wheat culture, with a purity of 99.01%. The study had provided an easy-operating and cost-effective method to isolate an expensive compound in a simple way.

Review of Alloy Membranes/Films for Hydrogen Separation or Purification

Hydrogen separation and purification are two important chemical processes in the extensive application of hydrogen energy. Membrane technology has opened up a potential solution to the problems of separation and purification in an energy effective way. Membranes of adequate hydrogen permeability, good thermal and mechanical stability are the key to successful application of membrane technology in hydrogen separation and purification. In this paper, the relative parameters concerning hydrogen permeability, the development of different types of membranes namely: palladium composite membranes; V-based alloy membranes, specific functionality embraced alloy membranes, metal hydride (MH) thin films and fabrications, were reviewed and discussed. Pd-free membranes are found to be the ideal alternatives. Suitable MH thin films with mono- or multi-layer microstructures produced by novel fabrication techniques, is likely to be the promising candidates due to possessing properties distinct from those of bulk materials in membrane form.

Separation and Purification of Total Phloroglucinols in Dryopteris crassirhizoma with DM-130 Macroporous Adsorption Resin

To improve the purity of the total phloroglucinols from Dryopteris crassirhizoma extracts, the separation and purification conditions of the total phloroglucinols from Dryopteris crassirhizoma were studied with DM-130 macroporous adsorption resin in this study. Adsorption rate, elution rate and purity of the total phloroglucinols were used as indexes to investigate the adsorption and desorption capacity of the total phloroglucinols with DM-130 macroporous adsorption resin. Through the study, the optimum sample concentration of the total phloroglucinols and maximum sample volume were 1.5 mg·mL^-1 and 7 BV （210 mL）, respectively. The optimum desorption conditions were achieved by using 80% ethanol as desorption solvent at elution flow rate of 1.0 mL·min^-1. The result showed DM-130 macroporous adsorption resin performed effective adsorption and desorption. After purification, the purity of the total phloroglucinols increased by 11.5-fold.

Separation and Purification of Monascus Pigments from Red Yeast Rice

It is difficult to extract beneficial components from Monascus pigments due to their complex composition. The low purity of Monascus pigment preparations limits their further application in research and production. Therefore, this study was conducted to optimize the conditions for extraction and isolation of Monascus pigments from red yeast rice, to improve the purity of Monascus pigment preparations. Three fractions were isolated using column chromatography from red yeast rice, they were red, orange and yellow respectively. Then, the three fractions were analyzed for composition and purity using thin layer chromatography and liquid chromatography-mass spectrometry(LC-MS). The chromatograms revealed that the yellow and orange fractions had complex compositions that were difficult to be separated, while the red fraction consisted of fewer components. Finally, a single component was isolated from the red fraction using a thin layer chromatography plate, identified as monascorubramine according to its molecular mass.

Design and optimization of an integrated process for the purification of propylene oxide and the separation of propylene glycol by-product

It is difficult to separate the methanol and hydrocarbons in the propylene oxide(PO)purification process due to their forming azeotrope.As for this,a novel PO separation process,in that the deionized water is employed as extractant and 1,2-propylene glycol(MPG)that is formed from the PO hydrolysis reaction is recovered,is presented in this work.The salient feature of this process is that both the non-catalyzed reactions of PO hydrolysis to form MPG and dipropylene glycol(DPG)are simultaneously considered and MPG by-product with high purity is obtained in virtue of the deionized water as reflux liquid and side take-off in MPG column.In addition,the ionic liquid(IL)extractant is screened through the conductorlike screening model for segment activity coefficient(COSMO-SAC)and the comparisons of separation efficiency between the IL and normal octane(nC_(8))extractant for the separation of PO and 2-methylpentane are made.With the non-random two-liquid(NRTL)thermodynamic model,the simulation and optimization design for the full flow sheet are performed and the effects of the key operation parameters such as solvent ratio,theoretical stages,feeding stage etc.on separation efficiency are detailedly discussed.The results show that the mass purity and the mass yield of PO can be up to 99.99%and 99.0%,and the condenser duty,reboiler duty and PO loss in the process with IL extractant can be decreased by 69.66%,30.21%and 78.86%compared to ones with nC_(8).The total annual cost(TAC)calculation also suggests that the TAC would be significantly reduced if using IL in replace of nC_(8) for the investigated process.The presented results would provide a useful guide for improving the quality of PO product and the economic efficiency of industrial plant.

Separation and Purification of Dodecanedioic Acid from Its Homologous Compounds by Falling Film Crystallization

Separation and purification of dodecanedioic acid (DDDA) from its homologous compounds were studied experimentally by falling film crystallization (FFC). The influences of various operation parameters, including crystallizing time, flow rate of melt and temperature of glycerine bath, on purity of DDDA and crystallizing rate were investigated. Over 99% (by mole) DDDA was obtained for a feed composition of 96% (by mole). The main factors affecting the separation efficiency are flow rate of melt and temperature of glycerine bath. The crystallizing layer of DDDA was further purified by sweating and blasting. A set of optimized operation data are provided for better understanding the mechanism of heat and mass transfer in FFC, and for further industrial application of DDDA purification process.

KAOLIN CLAY PURIFICATION BY DRY HIGH GRADIENT MAGNETIC SEPARATION

A new method-dry High Gradient Magnetic Separation （HGMS）-to remove iron from ultrafine kaolin powder is described. A new kind of disperser, which breaks down the particle clusters in the powder by high speed gas flow from an air compressor, is used to completely disperse the powders. The dispersed particles are passed through vibrating HGMS by a vacuum pump to remove the iron. The magnetic and nonmagnetic fractions are separately collected by cloth collectors. Dry HGMS laboratory experiments are carried out. A product containing 0.90％ Fe2O3 was obtained, and the recovery was 70％.

Advances in Researches of Extraction, Separation, and Purification Technologies for Total Saponins of Panax notoginseng

Total saponins of Panax notoginseng have the functions of promoting blood circulation and removing phlegm, thus they have high medicinal value. There are many different extraction methods in the extraction and separation of total saponins of P. notoginseng . The extraction methods of total saponins of P. notoginseng are mainly divided into traditional extraction methods, modern extraction methods and compound extraction methods.

Separation and purification of proteinases from Gastric Mucosa of Northern Sheatfish,Silurus soldatovi

The separation and purification method for pepsin of Northern Sheatfish (Silurus soldatovi) was established by using the combination technology of salting-out,gel chromatography and gel electrophoresis,and the enzymic properties were also analyzed.The experimental results indicated that 28% and 56% (NH4)2SO4 saturation could separate the activated protease from the pepsin extract of gastric mucosa of Sheatfish (Silurus soldatovi) ;compared with the homogenate extraction,the pepsin specific activity of purified extraction by Sephadex G-75 gel chromatography system increased 598 fold,was 5 times higher than that of activated liquid,and the total production rate was 10.1%.The purified pepsin liquor at the conditions of pH3.3 0.01 M alanine-formic acid buffering solution,60 cm chromatography column,and the flowing rate of 0.8 ML/min was analyzed by SDS-PAGE,which indicated that there were two bands and the molecular weight was 34.0 kDa and 40.4 kDa,respectively.There were two peaks in the enzyme activity determination of the separated collecting liquor in gel chromatography,and the SDS-PAGE showed the concentrations of the two proteins was different,which indicated that it existed at least two pepsins in the gastric mucosa of Sheatfish (Silurus soldatovi).

Separation and Purification of GST-glycerol-3-phosphate Dehydrogenase

In order to investigate the expression of glycerol-3 -phosphate dehydrogenase by GCY1 gene in recombinant Saccharomyces cerevisiae, induction culture of the S. cerevisiaestrain was performed with SD-URA 2% galactose, 3 × YP ＋ 6% glucose, SC-URA 2% galactose, and SC-URA 2% galactose ＋ 5% NaCI glyeerol-3-phosphate dehydregenase, the cultured S. cerevisiaewas comminuted followed by full-automatic high-speed purification, and SDS-PAGE gel electrophoresis was performed for molecular weight of the GST fusion protein. The results showed that after shaking culture of the S. cerevisiae containing GCY1 at 25 ℃, the OD values of its 3 × YP ＋ 6% glucose culture and SC-URA 2% galaetose ＋ 5% NaC1 culture were 8.75 and 7.35, respectively. It was shown by purification with a Profinia low-pressure liquid chromatograph that only the S. cerevisiae cultured in SC-URA 2% galactose ＋ 5% NaC1 medium expressed glycerel-3-phosphate de- hydrogenase, the molecular weight of which was detected as 65 ku by SDS-PAGE gel electrophoresis.

Separation and Purification of Tobacco Peroxidase I from Nicotiana Tobaccum

A new isoenzyme of tobacco peroxidase(TOP) I was purified from tobacco (K326) by using acetone powder, ammonium sulfate precipitation and column chromatography on DEAF-52 cellulose, Sephadex G-75 and DEAE-Sephadex A-50. It is an iron-protein containing haemachrome, whose molecular weight is 21888.5 and the isoelectric point is 3.5. The optimum pH value and temperature of this enzyme is 6.0 and 45℃ respectively. The enzyme is stable in the pH range from 3.0 to 10.0 and has a favorable thermostability.

Experiments and model development of p-nitrochlorobenzene and naphthalene purification in a continuous tower melting crystallizer

With the increasing demand for high-purity products,the industrial application of melt crystallization technology has been highly concerned.In this study,the purification process of nitrochlorobenzene binary eutectic system(NBES)and naphthalene–benzothiophene solid solution system(NBSSS)in tower melting crystallizer is analyzed,and a mathematical model of crystallization process is established.The key parameters in terms of feed concentration,crystal bed height,reflux ratio and stirring speed effi-ciency on purification effects were discussed by the established model.The results show that the concentration of p-nitrochlorobenzene was purified from 90.85%to 99.99%,when the crystal bed height is 600 mm,the reflux ratio is 2.5,and the stirring speed is 12 rmin^(-1).The naphthalene concentration is purified from 95.89%to 99.99%,when the crystal bed height is 400 mm,the reflux ratio is 1.43,and the stirring speed is 16 rmin^(-1).The quality of the model is evaluated by the ARD(average relative deviation).The minimum ARD values of the NBES and NBSSS are 2.39%and 5.22%,respectively,indicating the model satisfactorily explains the purification process.

One-step ethylene separation from ternary C_(2) hydrocarbon mixture with a robust zirconium metal-organic framework

One-step separation of high-purity ethylene(C_(2)H_(4))from C_(2) hydrocarbon mixture is critical but challenging because of the very similar molecular sizes and physical properties of C_(2)H_(4),ethane(C_(2)H_(6)),and acetylene(C_(2)H_(2)).Herein,we report a robust zirconium metal-organic framework(MOF)Zr-TCA(H3TCA=4,4',4"-tricarboxytriphenylamine)with suitable pore size(0.6 nm×0.7 nm)and pore environment for direct C_(2)H_(4) purification from C_(2)H_(4)/C_(2)H_(2)/C_(2)H_(6) gas-mixture.Computational studies indicate that the abundant oxygen atoms and non-polar phenyl rings created favorable pore environments for the preferential binding of C_(2)H_(2) and C_(2)H_(6) over C_(2)H_(4).As a result,Zr-TCA exhibits not only high C_(2)H_(6)(2.28 mmol·g^(-1))and C_(2)H_(2)(2.78 mmol·g^(-1))adsorption capacity but also excellent C_(2)H_(6)/C_(2)H_(4)(2.72)and C_(2)H_(2)/C_(2)H_(4)(5.64)selectivity,surpassing most of one-step C_(2)H_(4) purification MOF materials.Dynamic breakthrough experiments confirm that Zr-TCA can produce high-purity C_(2)H_(4)(>99.9%)from a ternary gas mixture(1/9/90 C_(2)H_(2)/C_(2)H_(6)/C_(2)H_(4))in a single step with a high C_(2)H_(4) productivity of 5.61 L·kg^(-1).

Ethylene purification in a metal–organic framework over a wide temperature range via pore confinement

The separation of C2H4from C_(2)H_(6)/C_(2)H_(4)mixture is of great importance but difficult and energy intensive. Adsorptive separation provides an alternative approach to ameliorate this situation. Here, we report a microporous metal–organic framework(MOF) BUT-315-a as a C_(2)H_(6)-selective adsorbent for the separation of C2H6/C2H4gas mixture. BUT-315-a combines good IAST selectivity of 2.35 with high C_(2)H_(6)uptake of 97.5 cm^(3)g^(-1), giving superior high separation potential ΔQ(2226 mmol L^(-1)) for equimolar C_(2)H_(6)/C_(2)H_(4) at 298 K. Impressively, such excellent performance can be preserved at higher temperatures of 313 and 323 K to accommodate industrial conditions. Efficient dynamic separation performance of BUT-315-a has been demonstrated by column breakthrough experiments under varied temperatures and gas ratios. Theoretical calculations further reveal multiple synergistic interactions between C_(2)H_(6) and the framework. This work highlights a new benchmark material for C_(2)H_(6)/C_(2)H_(4)separation and provides guidance for designing adsorbent for separation applications.

AB-8大孔树脂-C18柱联用分离干腌牛肉抗氧化肽的研究

该文利用盐酸提取法提取了干腌牛肉多肽,借助AB-8型大孔树脂及C18球形硅胶柱的分离纯化出4种抗氧化肽,利用分子对接模拟了4种抗氧化肽与超氧化物歧化酶(superoxide dismutase,SOD)的结合位点。利用盐酸提取法提取了抗氧化肽并测试其在1、2、3、4、5 mg/mL的抗氧化能力,发现在5 mg/mL时,DPPH自由基、ABTS阳离子自由基和超氧阴离子自由基(·O_(2)^(-))清除率分别为86.24%、35.62%和54.34%。对比了AB-8、D101、S-8、X-S、HPD-500、NKA-9的吸附率与解吸率,AB-8的吸附率与解吸率最好,分别为92.55%和82.88%。研究优化了AB-8的上样流速、上样量、乙醇洗脱浓度和洗脱流速,在4 BV/h上样流速、39 mL上样量、75%(体积分数)乙醇溶液洗脱剂和1 mL/min洗脱流速时,可以分离出3个组分(A、B和C),测试3个组分的抗氧化能力,B组分的DPPH自由基、ABTS阳离子自由基和·O_(2)^(-)清除能力最高,分别为73.33%、21.01%和63.33%。对B组分进行C18柱分离,分离出4个抗氧化肽:FDGDF、TGPGPW、FLSDH和KPFDAK。与SOD(PDB ID;1E9O)进行分子对接,发现FDGDF、TGPGPW、FLSDH和KPFDAK均可以与SOD形成氢键,结合能分别为-6.7、-6.55、-6.6、-7.35 kcal/mol,1 mg/mL的FDGDF可以有效增加SOD活力11.64%,酶活力单位增加697 U/mL,研究结果为干腌牛肉制品的开发提供理论基础。

西罗莫司片中主要降解杂质的分离和鉴定

目的:从西罗莫司片中分离未知杂质,进行结构鉴定和初步生物学活性考察,提高西罗莫司片的质量。方法:采用硅胶柱层析法富集未知杂质粗品,再用制备型高效液相色谱仪进行纯化。应用紫外光谱、红外光谱、质谱、核磁共振谱等波谱分析法对其进行结构鉴定。用二倍稀释法测定其抗真菌活性,用SRB检测其抗肿瘤活性。结果:纯化获得未知杂质的纯度为96.8%,结构鉴定为断雷帕霉素。抗真菌和抗肿瘤活性低于雷帕霉素。结论:断雷帕霉素是西罗莫司片制备中的主要降解杂质,生物学活性低于西罗莫司。

混菌发酵茶籽抗氧化肽的分离纯化及其功能活性研究

为促进茶叶籽资源的深度开发利用,采用不同截留分子质量的超滤膜对混菌发酵茶籽多肽产物进行分级分离,比较茶籽多肽的抗氧化活性与其分子质量的对应关系;利用凝胶过滤色谱技术对茶籽多肽逐级纯化,获得特征性茶籽抗氧化肽,对其二级结构组成及相对含量进行分析,并考察其热稳定性和抗消化稳定性;以H_(2)O_(2)诱导小鼠胚胎成纤维细胞(MEF细胞)建立氧化损伤模型,评价茶籽抗氧化肽的细胞氧化损伤保护功能。结果表明:经超滤分级后,茶籽多肽的抗氧化活性与其分子质量呈负相关,分子质量小于1 kDa的TSP4组分具有最高的自由基清除能力;TSP4分子质量分布范围在90~849 Da之间,凝胶过滤色谱纯化得到的TSP4-b亚组分平均分子质量为446 Da,其二级结构中的β-折叠的相对含量从未发酵茶叶籽的16.59%上升至44.43%,α-螺旋则由未发酵茶叶籽的37.61%降至17.57%;TSP4-b经20~60℃热处理以及模拟胃肠消化后,自由基相对清除率仍可分别保持在90%及80%以上,具备良好的热稳定性及抗消化能力;中(0.5 mg/mL)、高(5.0 mg/mL)剂量的TSP4-b的介入可使H_(2)O_(2)诱导的MEF细胞存活率分别达到73.8%、82.4%。综上,所分离的茶籽抗氧化肽具有较强的抗氧化活性,对H_(2)O_(2)诱导的细胞损伤具有保护作用,在医药、保健食品等领域具有良好的发展潜力。

食用菌姬松茸多糖的分离纯化及结构分析

采用热水煮提、乙醇沉淀和离子交换-凝胶组合柱层析的方法,从食用菌姬松茸中提取分离纯化出了两种电荷和相对分子质量分布均一的姬松茸多糖级分WABM-N-a和WABM-A-b,对两种均一级分的结构进行了研究.结果表明:WABM-N-a级分以1,6-Galp构成主链骨架结构,同时存在较多的1,6-Glcp 1,3-Fucp结构和少量的1,4-Glcp,1,3-Glcp结构连接在Gal的O-3和/或O-4位上,且侧链上的Glc在O-3位上存在少量的分支.WABM-A-b级分为1,6-Glcp连接的葡聚糖结构,Glc在O-2,O-3和/或O-4位上可能均有分支,侧链结构可能为1,3-Glcp,1,4-Glcp,T-Glcp和1,6-Galp.

哈茨木霉β-葡聚糖酶诱导、纯化及对黄瓜幼苗的促生防病作用

在实验室条件下分别以β-葡聚糖、麦麸和黄瓜枯萎病菌(Fusarium oxysporum)细胞壁作为唯一碳源诱导哈茨木霉菌(Trichoderma harzianum)Th-30发酵产生β-葡聚糖酶,采用硫酸铵盐析和琼脂糖凝胶色谱柱层析法对β-葡聚糖酶进行分离纯化,以津研4号黄瓜为试验材料,探究β-葡聚糖酶对黄瓜幼苗抗性生理指标、形态指标的影响及黄瓜常见土传病害的防控作用。结果表明:不同诱导条件下木霉Th-30发酵产β-葡聚糖酶活性差异显著,经β-葡聚糖诱导发酵的粗酶液酶活性最高,发酵72 h时达75.63 U·mL^(-1);纯化的β-葡聚糖酶比活力为783.56 U·mg^(-1),是粗酶液的45.32倍;5倍液和10倍液β-葡聚糖酶可显著提高黄瓜幼苗的根系活力、游离脯氨酸含量、苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)、多酚氧化酶(PPO)活性以及根冠比和壮苗指数;β-葡聚糖酶10倍液处理对黄瓜立枯病、黄瓜枯萎病、黄瓜疫病、黄瓜猝倒病、黄瓜菌核病的防效为50.36%~80.63%。