树脂法富集分离蜂胶总黄酮

实验考察了7种大孔树脂及聚酰胺对蜂胶总黄酮的吸附率和解吸率,结果显示,AB-8树脂对蜂胶总黄酮有较高的吸附解吸能力,适合富集蜂胶总黄酮。实验还对影响AB-8树脂富集蜂胶总黄酮的各因素(吸附时间、吸附温度、解吸温度、洗脱剂乙醇浓度、洗脱剂用量)进行了研究,所得AB-8树脂对蜂胶总黄酮的富集工艺为:35℃水浴静态吸附5 h,75%乙醇7BV洗脱,总黄酮解吸率可达90%,所得蜂胶浸膏总黄酮含量达30%。     

大孔吸附树脂对喜树叶中喜树碱的纯化工艺研究

研究通过静态吸附/解吸实验对大孔吸附树脂进行筛选,优选AB-8大孔吸附树脂作为层析柱填料,并对其进行喜树碱纯化工艺研究;研究表明AB-8树脂对喜树碱的静态吸附率为95.31%;体积分数95%的乙醇静态解吸率为92.4%;最佳吸附条件为:上样液质量浓度为0.175mg/mL,上样液不调pH值,吸附流速为2BV/h,平衡吸附5h;最佳洗脱条件:体积分数95%乙醇,洗脱流速1BV/h,洗脱体积为8BV。在该工艺条件下,洗脱物中喜树碱质量分数为7.43%,洗脱率为83.1%。     

树莓叶片黄酮成分分离纯化研究

为纯化树莓叶片黄酮成分,比较了7种树脂静态吸附和解吸过程,筛选出合适的大孔树脂初步纯化树莓叶片总黄酮,优化了吸附和解吸条件.结果表明:AB-8大孔树脂对树莓叶片总黄酮有较好的吸附和解吸性能,其最佳工艺为上样液pH=6.0、流速2.0 mL·min-1,洗脱剂乙醇最适宜浓度为70％,流速1.5 mL·min-1,经AB-...     

大孔吸附树脂纯化化香树果序总黄酮工艺研究

以吸附量和解吸率为指标对9种大孔吸附树脂进行对比,H-327B是分离纯化化香树总黄酮的理想树脂;热力学、动力学研究表明,Langmuir模型描述化香树果序黄酮在大孔树脂上的吸附规律更为适宜,该吸附属单分子层吸附,提高温度有利于吸附的进行,吸附过程可自发进行;对吸附?解吸工艺条件优化研究表明:当上样质量浓度为8.9 mg/mL、流速为3 BV/h时,H-327B型树脂对化香树果序总黄酮的吸附量较大。采用体积分数90%乙醇水溶液进行洗脱时,用5 BV乙醇洗脱,解吸率达到65%。     

大孔吸附树脂对葡萄籽原花青素的吸附特性

从9种大孔吸附树脂中筛选出AB-8树脂对原花青素有较好的吸附和解吸性能。研究了原花青素在AB-8树脂上的吸附特性。静态吸附表明,吸附略有放热,平衡吸附时间为2 h,吸附行为更符合Langmuir等温式,用体积分数为50%的乙醇时解吸效果最好。当流速为1.5 BV/h时,动态泄漏吸附量比静态吸附量低15%,5BV可达到完全洗脱的目的,其原花青素的质量分数可达85.8%。     

大孔吸附树脂纯化紫花地丁总黄酮工艺研究

目的 :研究大孔树脂分离纯化紫花地丁总黄酮的工艺。方法:采用静态吸附-解吸法考察9种大孔树脂对紫花地丁总黄酮的吸附和解吸性能,筛选树脂型号;以总黄酮浓度为指标考察各因素对D101大孔树脂纯化紫花地丁总黄酮的影响。结果:选用D101型大孔吸附树脂,最佳工艺条件为:吸附流速为1 mL/min、上样量为110 mL(黄酮质量分数为1.93 mg/mL)和8BV的70%乙醇进行洗脱,并经3次工艺验证试验得紫花地丁总黄酮质量分数为61.84%、62.88%、61.96%。结论:该方法简单可行,分离效果好,可为工业生产提供参考。     

AB-8大孔树脂纯化柑橘皮总黄酮的研究

通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。     

AB-8大孔树脂纯化柑橘皮总黄酮的研究

通过静态吸附解吸实验以及动态吸附解吸实验,优化了AB-8大孔树脂纯化柑橘皮黄酮的工艺。结果表明,AB-8大孔树脂的静态吸附:饱和吸附量15 mg/g(以树脂湿重计),饱和吸附时间180 min,样液最佳p H 5. 5,样液中黄酮浓度高有利于吸附; AB-8大孔树脂的静态解吸液乙醇最佳浓度为80%,黄酮解吸速度很快,少量解吸液可较好地洗脱而得到高浓度黄酮溶液;动态吸附流速3 BV/h,解吸流速6 BV/h,纯化柑橘黄酮的回收率为75. 07%,纯化倍数为4. 14;柑橘皮黄酮主要以糖苷形式存在,苷元较少。     

大孔吸附树脂分离纯化猪毛菜总黄酮及其抗氧化活性

采用不同大孔吸附树脂分离纯化猪毛菜总黄酮,并对纯化后的总黄酮进行体外抗氧化活性测试。通过考察影响树脂静态和动态吸附与洗脱的主要因素,确定猪毛菜总黄酮分离纯化优化工艺条件。静态吸附实验表明,AB-8树脂分离纯化效果较好,并且吸附符合Langmuir和Freundlich方程。动态吸附和解吸的最佳工艺条件为:上样液质量浓度1.25 g/L、p H=4.5、上样流速2 m L/min、上样量2.5 BV(BV指树脂柱内装载树脂的体积)、洗脱剂为体积分数80%的乙醇溶液、洗脱流速1.0 m L/min,洗脱剂用量4 BV。所得洗脱液中黄酮质量分数从纯化前10.20%增加到纯化后51.89%,回收率为84.43%。体外实验表明,纯化后的黄酮可以清除羟自由基和超氧阴离子自由基,并有较好的还原力。纯化后的黄酮可以作为一种潜在的天然抗氧化剂。     

大孔吸附树脂纯化芹菜黄酮的研究

研究6种大孔吸附树脂对芹菜黄酮类物质的吸附和解吸性能,筛选出吸附率较高的XAD-16树脂,并对XAD-16树脂静态吸附和动态吸附解吸工艺做了研究。优化出XAD-16树脂纯化芹菜黄酮的最佳工艺参数为：室温下吸附;上样流速4 BV/h,在上样浓度0.55 mg/mL下,上样体积为15倍柱床体积;洗脱溶剂采用体积分数50%的乙醇,洗脱流速为6 BV/h,洗脱液量为4倍柱床体积。     

Characterisation of separated melamine—formaldehyde adducts (methylolmelamines) and adduct mixtures by h.p.l.c. and by n.m.r. and u.v. spectroscopy

Most of the individual methylolmelamines that occur in melamine–formaldehyde adduct mixtures have been separated by preparative high-performance liquid chromatography (h.p.l.c.) and recovered in amounts sufficient to allow their characterisation by high-field ¹H- and ¹³C-n.m.r. Particular attention has been paid to the chemical shifts of the aromatic azine carbons of the melamine nuclei. These carbon shifts are shown broadly to be in agreement with some values previously published, but additional assignments have been made. It is shown that a satisfactory quantitative analysis of the methylolmelamines in a melamine–formaldehyde adduct mixture can be carried out either by h.p.l.c. or by ¹³C-n.m.r.     

In-situ monitoring of the stabilization with hydrogen of free radicals thermally induced from coal using high pressure e.s.r., d.t.a. and p.d.a. equipment

High temperature, high pressure e.s.r. measurements of the hydrogenation reaction of Taiheiyo coal in the presence of catalysts were carried out to understand the stabilization of thermally and/or catalytically induced free radicals. A decrease in free radical concentration with increasing temperature was observed for ZnCl₂ and SnCl₂ · 2H₂O catalysts at 10MPa under hydrogen gas. High pressure modified single-cell d.t.a. and p.d.a. equipment augmented the uniquely designed high temperature, high pressure e.s.r. cell. The hydrogenation reaction was monitored under the same experimental conditions as for e.s.r. From the results of the combination of high temperature, high pressure e.s.r. with high pressure d.t.a. and p.d.a., it was established that H₂ molecules can react efficiently with free radicals from coal molecules created by the presence of ZnCl₂ and SnCl₂ · 2H₂O catalysts.     

球形壳聚糖固定化糖化酶的研究

研究了以球形壳聚糖作载体固定化糖化酶的方法，探讨了戊二醛用量，酶量，温度，pH值对固定化效果的影响。     

Two-dimensional n.m.r. characterization of cycloaliphatic epoxy resins

The cycloaliphatic epoxy resins were studied by various two-dimensional nuclear magnetic resonance (2D n.m.r.) spectroscopies. The ¹³C n.m.r. spectra of the epoxy resins were assigned by using DEPT and 2D INADEQUATE techniques and the ¹H n.m.r. spectra were assigned by using 2D ¹H---¹H and ¹H---¹³C COSY techniques. Complete characterization of the samples synthesized by the oxidation of cyclohexene derivatives not only revealed the existence of the stereochemical isomers resulting from the structural difference of the oxide rings in the samples but also provided the composition ratio of the isomers.     

Quench solvent evaluation: An e.s.r. study

An in-situ radical-quenching experiment was performed in an e.s.r. microwave cavity by using a solution flow system. Diphenylmethyl radicals produced from pyrolysis of 1,1,2,2-tetraphenylethane were quenched by several H-donor solvents. Among the solvents used, indan was the fastest in quenching, followed by hydrophenanthrene, tetralin, mesitylene and cumene in decreasing order of quenching rate.     

Evaluation of a delayed coking process by H and C n.m.r. spectroscopy: 2. Detailed interpretation of liquid n.m.r. spectra

The ¹H and ¹³C nuclear magnetic resonance (n.m.r.) spectra of a delayed coking feedstock and products, presented in a previous paper, are analysed here in detail by matching results from inspection of both nuclei. The conventional spectra of whole samples are used in combination with elemental analysis data, and substantial agreement is obtained. Differences are explored to yield valuable information. Interpretation of some band assignments is modified to account for new results. This approach results in a detailed quantitative estimation of a few key structures that contain the main functional groups that characterize these petroleum fractions.     

E.s.r. spectra of eastern oil shales

E.s.r. spectra of several oil shales from eastern and western USA have been measured at 9 and 25 GHz. The spectra of the western shales were similar to previously reported spectra and consist of a Mn²⁺ signal and a featureless organic signal. The eastern spectra consist of a V⁴⁺ signal and a complex and unusual organic signal consisting of at least four component signals. The organic signal has been characterized in terms of g factor, line-width and saturation characteristics. The effect of oxygen on the signal has also been examined. Electron nuclear double resonance (ENDOR) signals have been obtained from the organic signals of the eastern oil shales.     

An h.p.l.e. and m.s. analysis of distillate fractions of neutral oil from hydrogenated Akabira coal to elucidate chemical structures

Akabira coal-derived neutral oil was separated into 25 narrow boiling range fractions covering 183–423 °C, and subsequently separated into compound class fractions : alkanes, monoaromatics, naphthalene-type diaromatics, fluorene-type diaromatics and tri- and/or tetraaromatics, by high performance liquid chromatography (h.p.l.c.). The compound type analyses of the distillate/h.p.l.c. fractions were performed using electron impact mass spectroscopy (e.i.m.s.) or field ionization mass spectroscopy (f.i.m.s.). Aromatic/hydroaromatic compound types and the alkyl side-chain carbon distribution of the distillate/h.p.l.c. fractions were clarified, based on the separation behaviour of h.p.l.c. and the type analyses according to Z value by m.s. By the distillation/h.p.l.c./m.s. method, coal-derived oil was characterized in terms of the distribution of the numbers of aromatic rings, naphthenic rings and carbons of alkyl groups attached to these rings. The variations in chemical structure in a compound class with distillation temperature are discussed in terms of these chemical structural factors.     

活性染料SEFR值与中性固色工艺研究

根据活性染料染色特征值S．E．F．R．选择适用于中性固色工艺的活性染料，结果表明，S值高和低的活性染料对碱的浓度和温度敏感，对固色率的影响较为杂乱，但在温度为80℃时，这类染料的固色率均达到峰值：染色特征值在50-60范围内的活性染料适用于中性固色、以甲酸钠为中性固色剂对活性染料进行中性固色实验，其固色率均可达到60%左右．各项牢度均达到标准。最佳工艺条件为：甲酸钠：15g／L；尿素：20g／L；双氰胺10g／L，固色温度85℃：浴比：1：20。     

Structural characterization of Saudi Arabian heavy crude oil by n.m.r. spectroscopy

Saudi Arabian heavy crude oil was separated into six fractions, including five distillate fractions (<93, 93–204, 204–260, 260–343 and 343–454 °C) and a >454 °C distillation residue. Each fraction was analysed by ¹H and ¹³C n.m.r. spectroscopy, and combined gained information from these analyses provided reliable average structural parameters. These included estimation of aliphatic and aromatic content, average paraffinic chain length, and estimation of hydrogen, methyl and alkyl bearing aromatic carbons for each of the six fractions. The extent of branching in paraffinic chains and amount of aromatic bridgehead carbons were also calculated.