从芹菜中提取总黄酮的工艺分析

目的为充分利用芹菜食物资源，避免资源的浪费，探讨芹菜总黄酮的提取及鉴别方法。方法采用超声波乙醇浸提法从芹菜中提取黄酮类物质，对所提取的黄酮类物质进行验证，并用分光光度法测定含量。结果测得样品中总黄酮的含量C=0．2126mg／ml，回收率为100．3％，其纯度和产率均较高。结论该方法采用全物理过程，无任何污染，是提取芹菜黄酮类物质的有效途径。     

芹菜的总黄酮提取技术

目的为充分利用芹菜食物资源，避免资源的浪费，探讨芹菜总黄酮的提取及鉴别方法。方法采用超声波乙醇浸提法从芹菜中提取黄酮类物质，对所提取的黄酮类物质进行验证，并用分光光度法测定含量。结果测得样品中总黄酮的含量c=0．2126mg／ml，回收率为100．3％，其纯度和产率均较高。结论该方法采用全物理过程，无任何污染，是提取芹菜黄酮类物质的有效途径。     

含苯磺酰基酰胺螯合纤维的制备及对Pd(Ⅱ)的吸附

以聚丙烯腈和苯磺酰胺为原料合成了一种含苯磺酰基酰胺的螯合纤维,讨论了反应时间、温度及反应物配比等因素对反应的影响,用红外光谱对产物的结构进行了确证。利用螯合纤维分离柱从水溶液中分离富集痕量的Pd(Ⅱ)离子,用电感耦合等离子体原子发射光谱仪检测,回收率在95%以上;考察了螯合吸附剂的富集酸度,洗脱条件和吸附容量等吸附性能,结果表明,制备的螯合型吸附剂对Pd(Ⅱ)离子的吸附性能良好。     

多种植物油中黄酮和角鲨烯分布UPLC研究

该文采用超高效液相色谱(UPLC)技术分别建立植物油中黄酮类物质和角鲨烯的定量方法,考察常见13种植物油中黄酮和角鲨烯的分布规律。实验采用70%的甲醇预处理植物油样,制备供试品溶液;经Acquity UPLC的C18柱(2.1 mm×100 mm,1.7μm)分离,以甲醇和0.8%磷酸溶液分别为流动相A相和B相,经梯度洗脱,于360 nm处,分离检测黄酮类组分。采用正交试验优化出植物油中角鲨烯的最佳皂化条件,经Acquity UPLC的C8柱(2.1 mm×100 mm,1.7μm),流动相为乙腈-水(97:3),于波长210 nm分离检测角鲨烯。结果表明:所建方法能有效分离黄酮组分或角鲨烯,在黄酮浓度50~600 ng/m L范围内5种黄酮各自线性关系良好(r≥0.999),检测限和定量限为10.2~15.6 ng/m L和33.6~48.6 ng/m L,平均加样回收率在97.75%~102.21%,重复性(RSD)为2.79%~7.75%;在角鲨烯浓度1~350μg/m L范围内;角鲨烯的线性相关良好(r≥0.999),检测限和定量限分别为27.3 ng/m L和81.9 ng/m L,平均加样回收率为88.18%,重复性RSD为1.96%;13种植物油中能检出角鲨烯,其中橄榄油中最高;只有火麻籽油和沙棘油中检出所列5种黄酮,亚麻籽油检出槲皮素和木犀草素,橄榄油中检出木犀草素和异鼠李素;所建立方法是食用植物油中黄酮类组分或角鲨烯质量控制的好方法,提示植物油的生产工艺可能影响极性黄酮类组分的含量。     

大孔树脂-聚酰胺联用纯化桑葚花色苷

目的 为了得到纯度更高的桑葚花色苷.方法 以桑葚为研究对象,比较AB-8,D4020,D101,NKA-9,HPD100等5种大孔树脂对桑葚花色苷吸附和解吸性能的影响,确定最佳工艺条件.结果 HPD100大孔树脂是最合适的桑葚花色苷纯化物质,测得吸附率和解吸率分别为93.6％和37.9％;纯化工艺最佳条件为上样流速1.5 mg/mL、上样pH值2.4、乙醇体积100 mL、洗脱流速1.5 mg/mL、乙醇体积分数70％,在此条件下测得纯度为35.15％.运用聚酰胺树脂进行2次纯化得到的最佳纯化条件为上样pH值3.4、乙醇体积分数70％,在此条件下测得纯度为50.76％.结论 此最佳纯化工艺条件能够有效提高桑葚花色苷的纯度,为后续桑葚花色苷研究提供重要参考.     

大气中放射性氙的分离纯化系统研制

为实现大气中放射性氙的高效富集,利用制备色谱技术并结合吸附材料性能的差异,开展放射性氙分离纯化技术的研究,通过研究结果确定分离纯化系统的设计参数。实验验证氙分离纯化系统的性能,系统全流程的时间小于1h,获得的氙样品回收率大于90%,纯度高于95%,能满足放射性测量的要求。     

MOCVD尾气中氨气吸附回收的探讨与研究

主要探讨了以氯化钙为吸附剂吸附回收MOCVD尾气中氨气的效果。通过实验,研究了氯化钙状态、氨气分压、初始纯度对氨气吸附比、回收率以及回收纯度的影响。当使用粉末状氯化钙、氨气分压大于4 bar(1 bar=0.1MPa),初始纯度大于20%时,氨气吸附比达到5.8,回收率达到99.5%以上,回收的纯度达到99%以上。测试了氯化钙的吸附寿命,200次吸脱附氨气后吸脱附比只下降4%左右。     

香椿老叶中黄酮类和皂苷类物质的分离鉴定

目的对香椿老叶中的黄酮类和皂苷类活性物质进行分离鉴定,为进一步开发香椿老叶产品提供理论基础。方法使用柱色谱和高效液相色谱(High Performance Liquid Chromatography, HPLC)对香椿老叶中的物质进行分离纯化,并采用核磁共振(Nuclear Magnetic Resonance, NMR)和红外光谱(Infrared Spectroscopy,IR)对分离物质进行测定。结果香椿老叶中含有芦丁、表儿茶素、槲皮素、异槲皮素、番石榴苷等。利用显色反应初步定性鉴定出香椿皂苷中包括甾体皂苷和三萜皂苷。结论香椿老叶中含有丰富的黄酮类和皂苷类物质,具有广阔的开发前景。     

化妆品中苯甲酸、山梨酸、水杨酸和苯氧乙醇的测定

使用甲醇和0.02mol/L乙酸铵水溶液作流动相梯度洗脱,C18柱,测定化妆品中的苯甲酸、山梨酸、水杨酸和苯氧乙醇,方法与对羟基苯甲酸酯无干扰,实现基线分离,回收率在94～107%,变异系数<2%。检测低限为25mg/kg。     

吸附制冷用复合吸附剂原料配比优化及吸附机理探讨

采用混合法制备用于吸附制冷过程的复合吸附剂;用静态法和真空重量法测定水或乙醇在自制复合吸附剂上的平衡吸附量;用热分析天平测定了复合吸附剂的脱水或脱乙醇的DTA曲线峰端温度.以平衡吸附量和DTA曲线峰端温度作为考核指标,通过正交实验优化自制复合吸附剂原料配比.优化结果为:以硅胶(M4)、氯化锶(M10)和凹凸棒土(M3)等为主要吸附材料的复合吸附剂,最适宜配比为:M10-40%,M3-20%,M4-20%,其它20%,扩孔剂-E2.水在复合吸附剂M4-0132上的吸附量约为13x的2～3倍;乙醇在M1-0001上的平衡吸附量约为活性炭2.5～4倍.以吡啶为探针分子,用TG-DTA-DTG分析法分析吸附剂的复合现象及吸附机理.探讨结果表明:增加复合吸附剂弱吸附中心数,可显著降低其脱附温度.     

Separation of U,Pu, and Am recovered from mixed oxide (MOX) fuel by countercurrent chromatography

The separation of U, Pu, and Am recovered from MOX fuel with the adduct of HNO₃ with N,N′-dimethyl-N,N′-dioctylhexylethoxymalonamide by countercurrent chromatography (CCC) was studied. Solutions of N,N′-dimethyl-N,N′-dibutyldodecylethoxymalonamide in dodecane were used as stationary phase. The separation of U, Pu, and Am was carried in both isocratic and stepwise elution modes. The better separation of actinides and their higher radionuclidic purity are reached with stepwise elution. The first eluate fraction contained only Am (100%). The second eluate fraction contained U (100%) and Pu (0.7%). The third eluate fraction contained 99.3% of Pu.     

Intraparticle protein diffusion effect on gradient elution chromatography

The diffusion of proteins in adsorbent particles is an important step in gradient elution processes used for protein purification. A mathematical model, which takes into account the combined effects of axial dispersion, film mass-transfer resistance, intraparticle diffusion and adsorption equilibrium, was used to simulate the gradient elution process in a diethylaminoethyl ion-exchange chromatography. The effects of three important factors: intraparticle diffusivity, adsorbent particle diameter, and linear gradient slope on the separation of β-lactoglobulin A and β-lactoglobulin B were investigated individually. The restricted diffusion correlation was used to estimate protein intraparticle diffusivities in polymer matrices using the molecular weight of the protein and the polymer concentration (Boyer, P. M. and Hsu, J. T. AIChE J. 1992, 38, 259). The combined effects of these three factors on the resolution of β-lactoglobulin A and β-lactoglobulin B separation were also studied. A general strategy for design and optimization of gradient elution process for biochemical separations was suggested based on our investigation.     

Fast and quantitative recovery of hydrophobic and amphipathic peptides after incorporation into phospholipid membranes

A new method that allows fast and quantitative recovery of hydrophobic or amphipathic peptides, or both, after their intimate incorporation into lipid membranes, is proposed. It relies on the use of small Sep-Pak cartridges and simple chromatographic handling. Peptides selected for this study are the 35 amino acid transmembrane domain of the Neu/erbB-2 protein and its point mutated (V664E) analogue expressed in some cancers, the 25 amino acid BH4 domain from the Bcl-2 antiapoptotic protein and the 15 amino acid Catestatin segment from chromogranin A found to have antimicrobial capabilities. Incorporation of peptides into membranes is accomplished using organic solvent cosolubilization and several cycles of freeze-drying/hydration from aqueous solution. For the hydrophobic peptides, separation from the membrane is performed on Sep-Pak C2 columns in two steps: (i) water/methanol elution of lipids and (ii) peptide elution using aprotic solvents (acetonitrile, 2-propanol). For amphipathic peptides, separation is performed on Sep-Pak C(18) columns using selective elution in one single step: water/methanol elution to recover first the peptide and then the lipids. Peptide and lipid recovery after all purification steps range from 60 to 80%, with peptide purity above 96%. This new method is simple, inexpensive, and very fast: a 10-mg membranous mixture containing 10% (w/w) peptide may be separated in 20-30 min.     

Adsorption of Direct Red 80 dye from aqueous solution onto almond shells: effect of pH, initial concentration and shell type

The adsorption of Direct Red 80 (DR 80) dye from aqueous solution on almond shells as an eco-friendly and low-cost adsorbent was studied. The effect of shell type (internal, external and mixture shells), pH and initial dye concentration were considered to evaluate the sorption capacity of almond shell adsorbent. The mixture type of almond shell showed to be more effective. The adsorption studies revealed that the mixture type of almond shells remove about 97% of the DR 80 dye from aqueous phase after 1h of the adsorption process in a batch system. Although, pH changes did not appreciably affect the adsorption process but the maximum adsorption capacity of different types of almond shells (20.5, 16.96 and 16.4 mg/g for mixture, external and internal shells) were obtained at pH 2. However, in order to have a better control on the experimental conditions, pH 6 was selected for conducting all adsorption experiments. Initial dye concentration was varied from 50 to 150 mg/L. Higher concentrations of dye in aqueous solution reduced DR 80 dye adsorption efficiency of almond shells. Equilibrium data were attempted by various adsorption isotherms including Langmuir, Freundlich and Brunauer-Emmett-Teller (BET) models. It was found that the adsorption process by mixture type of almond shells follows the Langmuir non-linear isotherm. Furthermore, the experimental data by internal and external almond shells could be well described by the BET and Freundlich isotherm models, respectively. The pseudo-second-order kinetics provides the best correlation of the experimental data.     

Adsorptive removal of phenol from aqueous phase by using a porous acrylic ester polymer

The removal of phenol from aqueous solution was examined by using a porous acrylic ester polymer (Amberlite XAD-7) as an adsorbent. Favorable phenol adsorption was observed at acidic solution pH and further increase of solution pH results in a marked decrease of adsorption capacity, and the coexisting inorganic salt NaCl exerts positive effect on the adsorption process. Adsorption isotherms of phenol were linearly correlated and found to be well represented by either the Langmuir or Freundlich isotherm model. Thermodynamic parameters such as changes in the enthalpy (DeltaH), entropy (DeltaS) and free energy (DeltaG) indicate that phenol adsorption onto XAD-7 is an exothermic and spontaneous process in nature, and lower ambient temperature results in more favorable adsorption. Kinetic experiments at different initial solute concentrations were investigated and the pseudo-second-order kinetic model was successfully represented the kinetic data. Additionally, the column adsorption result showed that a complete removal of phenol from aqueous phase can be achieved by XAD-7 beads and the exhausted adsorbent was amenable to an entire regeneration by using ethanol as the regenerant. More interestingly, relatively more volume of hot water in place of ethanol can also achieve a similar result for repeated use of the adsorbent.     

Biostabilised icosahedral gold nanoparticles: synthesis,cyclic voltammetric studies and catalytic activity towards 4-nitrophenol reduction

A green and cost-effective biosynthetic approach for the preparation of icosahedral gold nanoparticles (AuNPs) using an aqueous leaf extract of Polygonum minus as reducing and stabilising factor is described. The reduction of Au³⁺ ions to elemental Au rapidly occurred and is completed within 20 minutes at room temperature. The size of the nanoparticles is highly sensitive to the AuCl₄^?/leaf extract concentration ratio and pH. Transmission electron microscopy and X-ray diffraction data indicated that the nanoparticles were in a crystalline shape (face-centred cubic), mostly icosahedral and nearly monodispersed with an average size of 23 nm. Cyclic voltammetric studies suggested that flavonoids, such as quercetin and myricetin present in the leaf extract had a tendency to donate electrons to Au³⁺ ions and the formation of elemental Au was possible due to the transfer of electrons from these flavonoids to Au³⁺ ions. Infrared absorption of the AuNPs and the leaf extract revealed that the oxidised (quinone) form of quercetin and myricetin were presumably the main stabilising agents in the formation of stable nanoparticles. The present biosynthesis of AuNPs was simple, rapid, cost-effective and environmentally friendly. The newly prepared biostabilised icosahedral AuNPs show good catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP).     

离子交换纤维对红霉素吸附特性的研究

采用自制的弱酸离子交换纤维对红霉素的吸附和洗脱性能进行了研究,考察了温度、酸度及吸附时间等因素对吸附性能的影响.实验结果表明,pH值为7.0时吸附性能最好.离子交换纤维对红霉素的吸附以液膜扩散为主.静态饱和吸附量为1.79×10~5u/g干纤维,等温吸附过程服从Langmuir和Freundlich等温吸附方程.pH值为7.0,流速为5.0ml/min时对红霉素的动态吸附容量为4.54×10~5u/g干纤维.选用0.1mol/L CH_3COONH_4溶液进行洗脱,当洗脱液流速为5.0ml/min,用量为80ml时洗脱率为92.5%.离子交换纤维的吸附量和洗脱率与大孔树脂类似,吸附速率远大于大孔树脂,能再生重复使用,是一种优秀的红霉素吸附材料.     

Removal of cationic dyes from aqueous solution using magnetic multi-wall carbon nanotube nanocomposite as adsorbent

A magnetic multi-wall carbon nanotube (MMWCNT) nanocomposite was synthesized and was used as an adsorbent for removal of cationic dyes from aqueous solutions. The MMWCNT nanocomposite was composed of commercial multi-wall carbon nanotubes and iron oxide nanoparticles. The properties of this magnetic adsorbent were characterized by scanning electron microscopy, X-ray diffraction and BET surface area measurements. Adsorption characteristics of the MMWCNT nanocomposite adsorbent were examined using methylene blue, neutral red and brilliant cresyl blue as adsorbates. Experiments were carried out to investigate adsorption kinetics, adsorption capacity of the adsorbent and the effect of adsorption dosage and solution pH values on the removal of cationic dyes. Kinetic data were well fitted by a pseudo second-order model. Freundlich model was used to study the adsorption isotherms. The prepared MMWCNT adsorbent displayed the main advantage of separation convenience compared to the present adsorption treatment.     

吸附法脱除R22的研究

通过吸附模拟实验,评价研究多种吸附剂对不同浓度二氟一氯甲烷(CHCl F2,简称R22)的吸附特性,并测试当要求R22净化精度小于4%体积分数时不同吸附剂的吸附容量,确定吸附法净化脱除R22的可行性及工艺条件。