提高薄层色谱制备量的研究

薄层制备色谱广泛用于纯化合物的制备。为提高其制备量,已做了许多改进,发展了不少新方法。 薄层的制备量除了厚度外,主要决定其面积的大小及所使用的吸附剂。通常用的20cm×20cm的硅胶薄层可以制备5—25mg样品。     

工业制备色谱在中药分离制备中的应用

概述了工业制备色谱柱型结构、填料、色谱技术特性的研究进展,对目前普遍使用的工业制备色谱的工作原理作了较为全面的评述,总结了动态轴向压缩色谱和模拟移动床色谱技术在中药分离制备中的应用和发展。     

药用微胶囊的制备

微胶囊技术是21世纪重点研究开发的高新技术之一,用途广泛。本文综述了微胶囊的制备原理及方法,着重阐述了采用超临界二氧化碳技术和溶剂蒸发法制备药物微胶囊的最新研究进展,介绍了超临界流体快速膨胀(RESS)法、超临界流体抗溶剂(SAS)法和气体饱和溶液微粒制备(PGSS)法的特点,总结了溶剂蒸发法制备微胶囊的原理和溶剂蒸发法制备药物微胶囊的工艺研究现状,分析了药物微胶囊的表征方法及性能,并对今后微胶囊技术的发展作了展望。     

溶液聚合制备微凝胶

溶液聚合制备微凝胶一般是在极稀溶液中进行,为突破这一限制,研究者们进行了多方面的尝试。本文主要从小分子单体溶液聚合、大分子单体溶液聚合及聚合物溶液交联三方面概括介绍了近年来溶液聚合制备微凝胶的研究状况,展望了溶液聚合制备微凝胶的研究发展前景。     

基于电迁移的蛋白质制备技术和方法新进展

基于电迁移的蛋白质制备技术是对一类分离和制备技术的统称,其特征是在电场的作用下对目标物质进行分离和纯化制备,这种技术在生物大分子和蛋白质组的研究中应用广泛。基于电迁移的制备技术主要包括制备型电泳、制备型电色谱、制备型等电聚焦和自由流电泳等。本文对每种制备型电迁移装置的设计、特点和基于该种装置的各种应用方法的优缺点进行了详细阐述,并列举了一些实例。另外,微量级制备型电泳因分离度高、回收率高以及高效快速的优点,在微量级生物样本分析中发挥着日益重要的作用,近年来备受关注,本文也着重关注了这方面的进展,并对基于电迁移的制备技术做了展望。     

锶盐纳米粉体的制备

锶盐纳米粉体是一种重要的工业固体材料。在简单回顾了近年来纳米材料的研究现状的基础上,总结了纳米碳酸锶、纳米钛酸锶以及其它纳米锶盐粉体的制备方法,同时对锶盐纳米粉体的原料来源和制备方法进行了展望。     

水性环氧树脂制备方法的研究进展

水性环氧树脂（WEP）具有无毒、无味和施工简便等优点,在涂料,塑料和建筑等领域有重要应用。综述了WEP的制备方法(自乳化法,外加乳化剂法和固化剂改性法)和制备机理。对比分析了3种制备方法的优劣。参考文献32篇。     

高分子负载胶态金属催化剂的制备

本文综述了高分子负载胶态金属催化剂的制备方法。高分子负载的胶态金属催化剂主要通过三种途径来制备,即直接从金属晶体制备,通过金属前身分子制备和金属有机单体的聚合。并对各种制备方法和所制得的催化剂的特点和特征进行了评述。     

碱式碳酸铜的制备

以CuSO4.5H2O和Na2CO3为反应原料制备碱式碳酸铜。学生通过查阅文献制定实验方案,经指导教师同意后开展实验。通过改变反应物的配比、体系pH、反应温度等条件制备碱式碳酸铜;通过测定产物Cu2+含量、TG/DTG曲线等对产物品质进行初步分析。用反应的产率和反应速率综合判断较优制备条件。     

葡萄糖氧化酶电极的制备

葡萄糖氧化酶电极的制备于秀娟，周定，郭京华（哈尔滨工业大学应用化学系哈尔滨１５０００６）关键词葡萄糖氢化酶，酶电极，制备酶与电极的连接即酶膜的形成是制备酶电极的关键步骤之一，有许多种方式［１～９］．葡萄糖氧化酶（ＧＯＤ）电极是研究较早和报道较多的一类...     

南瓜籽烘烤前后化学成分的分析

对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。     

二氧化钛纳米微粒膜光电化学行为的研究

利用不同的制备方法制备出二氧化钛纳米微粒膜，对二氧化钛纳米微粒膜的光电化学材为和产生的机理进行了研究．结果表明；二氧化钛纳米微粒膜除了具有传统半导体的光电化学性质外，还具有不同于传统半导体的光电化学性质这主要是出膜的微粒性引起的，可综合传统半导体和胶粒半导体两种模型来加以解释。     

ADSORPTION OF PHENOL AND NITROPHENOLS ON A HYPERCROSSLINKED POLYMERIC ADSORBENT

1. INTRODUCTION Nitrophenols are versatile raw materials in chemical industry and used in a great diversity of applications such as herbicides, insecticides and bactericides. Due to their extreme toxicity and adverse effect upon human and biota at very l…     

Determination of Ethosuximide,Phenobarbital, Carbamazepine,Carbamazepine Epoxide and Phenytoin in Serum by high performance liquid chromatography using Radially compressed Columns and an Aqueous methanolic mobile phase

Abstract

A liquid chromatographic method for the determination of antiepileptic drugs in serum is described. The drugs were adsorbed on activated charcoal from which they were recovered by extraction with methylene chloride. The organic extracts were evaporated to dryness and the residues were dissolved in small volumes of the mobile phase. The extracts were clean. Only trace amounts of endogenic compounds were detected. The chromatographic separation was performed with a radially compressed column (C18) that was used daily for several months.     

影响离子色谱测量准确性的因素

介绍了离子色谱测量过程中色谱条件的变化、样品前处理方法和操作过程等因素对测量结果准确性的影响,提出了相应的解决措施和校准方法.以实际样品测定为例介绍了样品前处理过程中待测组分浓度和形态的变化,对定量分析结果造成的误差及修正方法.     

ADSORPTION OF PHENOL AND NITROPHENOLS ON A HYPERCROSSLINKED POLYMERIC ADSORBENT

The adsorption of phenol and nitrophenols on hypercrosslinked polymeric adsorbent wasstudied as a function of the solution concentration and temperature. Adsorption isotherms of phenoland nitrophenols on hypercrosslinked resin were determined. These isotherms were modeledaccording to the Freundlich adsorption isotherm. The isotherms for phenol and nitrophenols onhypercrosslinked resin were assigned as L curves. Thermodynamic parameters were calculated for allphenol and nitrophenols. The kinetics experiment results showed that the adsorption rates were of thefirst-order kinetics. The rate constants at 303K were calculated.     

气相色谱仪验证要点

介绍分析仪器验证的基本概念和主要内容。总结了气相色谱仪验证中设计确认、安装确认、运行确认和性能确认的验证过程和要点,详细介绍了验证内容、具体项目、参考指标、参与人员、时间频次和要点等内容,指出了气相色谱仪验证需要注意的问题,提出了气相色谱仪验证工作的改进建议,为气相色谱仪器验证提供技术参考。     

单分散、规则球形Au@SiO2核-壳纳米粒的制备及光谱研究

采用3-巯基丙基三甲氧基硅烷作为联结剂,成功将单个金纳米粒子包在氧化硅壳中,制得Au@SiO₂核壳纳米粒子;该复合纳米粒子形貌呈球形、单分散性较好,金纳米粒子位于氧化硅球的中心,无团聚的金纳米粒子包覆在氧化硅壳中。采用透射电镜(TEM)对样品的形貌进行了表征,通过能量散射X-射线能谱(EDX)分析了目标物的化学成分,并对所得核壳纳米粒子的光谱性质进行了研究。     

Theoretical Studies on Electronic Structures and NMR Spectra of Oligo(4‐vinylpyridine)

Poly(4‐vinylpyridine) was determined to possess conductivity in the experiment. In order to understand properties of the polymer, a series of 4‐vinylpyridine oligomers were designed. The structures of these oligomers were optimized using density function theory (DFT) at B3LYP/6‐31G(d) level. The energy gaps and thermal stabilities of the oligomers were decreased when the chain lengths were increased. These properties were also decreased owing to the protonation of the pyridine ring. The holes were easily injected into the oligomers in the presence of hydrochloride. The electrons were conducted in the side chain composed of the pyridine rings rather than the main chain owing to the saturation of the main chain. The ¹³C nuclear magnetic resonance (NMR) spectra and nucleus independent chemical shifts (NICS) of these compounds were calculated at B3LYP/6‐31G(d) level. The chemical shifts of the carbon atoms connected with the nitrogen atoms in the protonated pyridines were moved upfield in comparison with those of the pyridines. The addition of hydrochloride on the pyridine ring in the oligomers led to the increase of the aromaticities, namely the aromaticities of the oligomers were obviously improved when the pyridine rings were protonated.     

Identification and quantification of the volatile constituents in Cnidium monnieri using supercritical fluid extraction followed by GC‐MS

The volatile components of Cnidium monnieri were obtained by supercritical fluid extraction (SFE) and analyzed by GC‐MS (identification and determination of metabolites). The compounds were identified according to their retention times and mass spectra. The effects of different parameters, such as extraction pressure, temperature, dynamic extraction time, flow rate of CO₂, on the SFE of C. monnieri extracts were investigated. A total of 14 compounds of SFE extracts were identified. Osthole (69.52%), bornyl acetate (10.03%), α‐pinene (4.71%), and imperatorin (2.42%) were the major compounds identified in C. monnieri SFE extracts. The quantitation of osthole and imperatorin were then accomplished. The linear calibration ranges were all 5–1000 μg/mL for osthole and imperatorin by GC‐MS analysis. The recovery of osthole and imperatorin were in the range 96.5–101.8%. The LODs for osthole and imperatorin were 1.0 and 0.6 μg/mL, respectively.