色谱累加进样分离实验条件的研究

在采用反相液相色谱或亲和色谱完成蛋白质等大分子分离时,根据溶质保留值随溶剂梯度变化曲线上突变点的差别,可以通过累加进样分离法进行样品制备或直接柱内富集分析,但这一方法并非在任意条件下、对任何样品都适用。该文根据不同形式的保留值方程从理论上探讨了样品保留值与进样时间差、梯度洗脱速率等实验条件之间的关系;结果表明：两次进样的出峰时间差与进样时间间隔成正比关系,也与其在等度情况下的容量因子有关。样品中的两种组分在间隔进样时的流出时间差主要由两组分的容量因子决定,当样品中存在两种以上保留性能相近组分时,若保证指定的分离度,进样时间间隔存在一极大值,超出该范围,分离条件将不能满足     

热分离进样/气相色谱-质谱法测定橄榄油中脂肪酸乙酯

建立了热分离进样/气相色谱-质谱快速测定橄榄油中4种脂肪酸乙酯(棕榈酸乙酯、硬脂酸乙酯、油酸乙酯、亚油酸乙酯)的分析方法。采用热分离进样技术进样,以DB-5MS色谱柱分离,选择离子监测模式检测。结果显示,4种脂肪酸乙酯在0.01～0.20 mg/L范围内线性良好(r²>0.999),方法的检出限(LOD)和定量下限(LOQ)分别为0.3 mg/kg和1.0 mg/kg,在低、中、高3个加标水平(1.0、2.0、10 mg/kg)下的回收率为82.4%～109%,相对标准偏差(RSD)为0.68%～6.8%。该方法灵敏度高,准确度和重现性好,可用于橄榄油中4种脂肪酸乙酯的快速检测。     

大体积进样离子色谱法对电厂水汽中痕量阴离子测定中两种分离柱的分离效果

对两种阴离子分离柱(AS 17-C和AS 19)在大体积进样(500μL)离子色谱法测定发电机组蒸汽中8种痕量阴离子中的分离效果做了试验和比较。现场取得的水样经滤膜过滤后直接进样,分别经上述两柱分离,并用不同浓度的氢氧化钾溶液作为流动相进行梯度淋洗,用抑制电导检测器检测。8种阴离子的质量浓度均在5~50μg·L-1范围内呈线性,检出限(3S/N)分别在0.07~0.73μg·L-1,0.08~1.9μg·L-1之间。用标准加入法做回收试验,测得回收率在99.6%~104%(AS 17-C柱)和98.0%~103%(AS 19柱)之间。     

大孔吸附树脂在微生物制药分离纯化应用上的最新进展

大孔吸附树脂在微生物发酵下游过程中,突显出分离纯化效能的优越性,在药学领域具有极其广泛的应用前景.本文通过查阅国内外文献介绍了大孔吸附树脂近3年来在大环内酯类、肽类等多类新抗生素、酶抑制剂、免疫抑制剂分离纯化应用上的最新进展.     

从高放废液中分离铯的研究进展

对采用沉淀法、离子交换法和溶剂萃取法从高放射性废液中分离Cs进行了综述,对这3种技术的优缺点进行了探讨,指出离子交换法具有实际的应用价值。     

双水相萃取法从风干香肠中分离提取蛋白酶

双水相萃取(ATPS)是近年来发展起来的蛋白纯化方法。为了扩展该方法适应领域,同时为风干香肠形成过程酶系的研究提供具体方法。本实验研究了运用双水相技术分离提取风干香肠中蛋白酶,对构成双水相体系中的PEG分子量、浓度和类型以及盐浓度的影响进行了分析。确定了双水相组成体系为20%PEG1000(m/m)和25%MgSO4(m/m),在此体系中风干香肠的蛋白酶主要分布在上相,最高酶活12.37U/μg;纯化倍数为4.61;回收率为85%。通过分子筛层析对比,表明风干香肠经过双水相分离提取杂蛋白峰被除去,而蛋白酶峰几乎未受到影响,说明该双水相体系萃取香肠中蛋白酶具有良好的专一性。调解双水相pH值对蛋白酶的萃取没有影响,而添加电解质NaCl反而产生不利影响。     

从混合离子中分离Fe,Al,Cd

从混合离子中分离Ｆｅ、Ａｌ、Ｃｄ邓凡政＊石影李霞陈岩（淮北煤炭师范学院化学系淮北２３５０００）关键词聚乙二醇，萃取剂，分离，金属离子１９９６－０４－２３收稿，１９９６－０７－０１修回利用水溶性高聚物聚乙二醇在无机盐存在下可以分成两相的性质［１］，选择...     

用聚苯胺膜从牛乳中直接分离黄嘌呤氧化酶

酶电极;新鲜牛乳;固定分离;用聚苯胺膜从牛乳中直接分离黄嘌呤氧化酶     

配位色谱法从葛根素浸膏中分离纯化葛根素

建立了采用配位色谱柱从葛根素浸膏中分离纯化葛根素的方法。以铜离子为中心离子,制备了中心离子含量为7%的配位色谱柱。样品上样于配位色谱柱后,以氯仿-甲醇（体积比为10∶1）混合溶剂洗脱,得到了较纯的葛根素,较之用传统的硅胶色谱柱纯化,纯度提高了11%,回收率提高了12%,且柱容量提高了两倍。配位色谱改变了葛根素在传统硅胶柱上的洗脱顺序,对目标物质的分辨率比传统硅胶色谱柱高。     

Temperature‐Triggered Phase Separation of a Hydrophilic Resilin‐Like Polypeptide

Temperature‐triggered phase separation of recombinant proteins has offered substantial opportunities in the design of nanoparticles for a variety of applications. Herein, the temperature‐triggered phase separation behavior of a recombinant hydrophilic resilin‐like polypeptide (RLP) is described. The transition temperature and sizes of RLP‐based nanoparticles can be modulated based on variations in polypeptide concentration, salt identity, ionic strength, pH, and denaturing agents, as indicated via UV–Vis spectroscopy and dynamic light scattering (DLS). The irreversible particle formation is coupled with secondary conformational changes from a random coil conformation to a more ordered β‐sheet structure. These RLP‐based nanoparticles could find potential use as mechanically‐responsive components in drug delivery, nanospring, nanotransducer, and biosensor applications.

     

系列类立方烷型Fe4S4簇合物的催化性质研究

系列类立方烷型Ｆｅ_４Ｓ_４簇合物的催化性质研究南玉明，徐吉庆，蔡辉，李淑芹（大庆石油学院石化系，安达１５１４００）（吉林大学化学系，长春１３００２３）关键词簇合物，类立方烷结构，催化１．前言对固氮酶的生物化学研究发现，固氮酶是由钼铁蛋白和铁蛋白组成的...     

树脂吸附层析法分离喜树果中的喜果甙

自 1 96 6年 Wall等 [1] 首次从喜树植物中分离出喜树碱后 ,至今已有 2 0多种化学成分从中分离出来 ,包括喜树碱 (Camptothecine,CPT)、 1 0 -羟基喜树碱、 1 1 -羟基喜树碱、 1 0 -甲氧基喜树碱、喜树次碱、白桦脂酸及喜果甙 (Vincoside- lactam,VCS- LT)等 [2 ] .研究表明 ,喜树碱类化合物和喜果甙均具有抗癌活性 [3～ 5] .从喜树果中分离喜果甙对充分利用我国丰富的喜树资源具有重要意义 .目前文献报道的分离提取喜果甙方法主要是溶剂萃取和氧化铝柱层析法 [6] ,过程复杂 ,收率很低 .本文采用树脂吸附法对喜果甙进行分离纯化 ,再经…     

Separation of Twenty Biogenic Amines and Derivatives by a High-performance Liquid Chromatographic Column Switching Technique with On-line Fluorimetric and Electrochemical Detections

Abstract

A new high-performance liquid chromatographic technique including the use of an automated column switching system has been developed for the study of dopamine, norepinephrine, epinephrine and serotonin and their related metabolites in biological samples. Through two runs, it has been possible to separate twenty derivatives and three internal standards which have to be added to samples prior to the extraction procedures. In each case, the column switching system allowed to obtain a clear separation of all the compounds, which will be of importance to avoid any expected interference from other endogenous substances, while decreasing the analysis time. By coupling on-line fluorimetric and electrochemical detections the specificity of the technique was enhanced, since the ratio of the responses of both detectors was an index of the purity of the peaks. In addition, fluorimetric detection was found of value to free the determination of some compunds from the effects of solvent front while electrochemical detection increased the sensitivity. Finally, the column switching system allowed a rapid cleaning of the columns between two analyses. A typical application to a human urine sample was shown.     

Assembly of a Nanoreactor System with Confined Magnetite Core and Shell for Enhanced Fenton‐Like Catalysis

Conventional solid catalysts for heterogeneous Fenton‐like reactions in bulk solution usually suffer from aggregation and vulnerability, which greatly lower the catalytic efficiency and hamper their practical application. Herein, we demonstrate a promising yolk–shell nanostructure with both the core and the shell composed of magnetite (designated as yolk‐like Fe₃O₄@Fe₃O₄/C) as a nanoreactor capable of accommodating the Fenton‐like reaction into its void space. Benefiting from the mesoporous shell and perfect interior cavity of this composite, reactants can access and be abundantly confined within the microenvironment where Fe₃O₄ sites are dispersed on the entire cavity surfaces, thus leading to a higher catalytic efficiency compared with the conventional solid catalysts in bulk solution. The chosen model reaction of chlorophenols degradation in the presence of the as‐prepared materials as well as hydrogen peroxide (H₂O₂) confirms this assumption. Under the optimal reaction conditions, more than 97 % 4‐chlorophenol (4‐CP) can be degraded in the Fe₃O₄@Fe₃O₄/C nanoreactor, whereas only 28 % can be achieved by using bare Fe₃O₄ particles within 60 min. Furthermore, owing to the existence of the outermost carbon layer and high‐magnetization properties, the nanoreactor can be re‐used for several runs. The synthesized nanoreactor displays superior catalytic activity toward the Fenton‐like reaction compared with the bare solid catalysts, and thereby holds significant potential for practical application in environmental remediation.     

Separation and Purification of Two Saponins from Paris polyphylla var. yunnanensis by a Macroporous Resin

An effective method for separating and purifying critical saponins (polyphyllin II and polyphyllin VII) from a Paris polyphylla var. yunnanensis extract was developed in this study which was environmentally friendly and economical. Static adsorption kinetics, thermodynamics, and the dynamic adsorption-desorption of macroporous resins were investigated, and then the conditions of purification and separation were optimized by fitting with an adsorption thermodynamics equation and a kinetic equation. Effective NKA-9 resin from seven macroporous resins was screened out to separate and purify the two saponins. The static adsorption and dynamic adsorption were chemical and physical adsorption dual-processes on the NKA-9 resin. Under the optimum parameters, the contents of polyphyllin II and polyphyllin VII in the product were 17.3-fold and 28.6-fold those in plant extracts, respectively. The total yields of the two saponins were 93.16%. This research thus provides a theoretical foundation for the large-scale industrial production of the natural drugs polyphyllin II and polyphyllin VII.     

尿素包合法分离蚕蛹油中多不饱和脂肪酸

蚕蛹是缫丝副产品,我国每年副产近20万吨干蛹[1].蚕蛹中油脂含量相当丰富,约占蚕蛹干基的25%～29%,且油脂总量的71.0%为不饱和脂肪酸,这些不饱和脂肪酸在人体内可合成二十碳五烯酸及二十二碳六烯酸,与鱼油中的EPA,DHA具有相似的抗衰老、健脑益智的功能,能维持正常的肾脏功能,治腰背疼痛、肌肉无力,预防动脉硬化、血脂升高等血栓疾病[2].     

Separation of zinc from aqueous samples using a molecular imprinting technique

In this article, the separation of zinc from aqueous samples by solid-phase extraction based on a molecular imprinting technique is described. Zn-imprinted polymer was prepared by free radical solution polymerisation in a glass tube containing ZnSO₄, morin, 4-vinylpyridine as a functional monomer, ethyleneglycoldimethacrylate as a cross-linking monomer, and 2,2′-azobisisobutyronitrile as an initiator. The obtained polymer block was ground and sieved (55–75 µm) and the Zn–morin complex was separated from polymer particles by leaching with 2M HCl. The synthesised polymer particles have been characterised by IR and differential scanning calorimetric studies either before or after leaching. The effects of different parameters, such as pH, adsorption and desorption time, type and minimum amount of the eluent for elution of the complex from polymer were evaluated. Extraction efficiency more than 99% was obtained by elution of the polymers with 10 mL of CH₂Cl₂–dimethyl sulfoxide (1 : 1, v/v). The detection limit of the proposed method was 2.9 µg L^?1. A dynamic linear range in the range of 25–200 µg L^?1 was obtained. The relative standard deviation was found to be below 9.2%. In addition, the influence of various cationic and anionic interferences on the complex recovery was studied. The method was applied to the recovery and determination of Zn in a few different real samples.     

手性选择剂萃取分离特布他林对映体

手性选择剂萃取分离特布他林对映体;特布他林对映体;手性选择剂萃取;中空纤维;膜分离