纤维素酶前处理没药挥发油成分的GC/MS分析

采用水蒸汽蒸馏法分别从未处理和纤维素酶前处理的没药中提取挥发油,利用气相色谱-质谱(GC/MS)联用技术对其挥发油成分进行分析。从中分别鉴定出38种和34种化学成分,用峰面积归一法通过数据处理系统得出各化学成分在挥发油中的质量分数,占挥发油总成分的67.95%和70.05%。     

棉籽化学成分的分析

采用索氏提取法对棉籽中棉籽油进行了提取,以气相色谱-质谱联用仪进行了分析,分离鉴定出10种脂肪酸,占棉籽油总量的99.52%。并对其主要成分进行了鉴定,主要化学成分为:棕榈酸26.68%,亚油酸66.05%。用蒸馏-萃取法提取棉花籽中挥发性物质,测得棉籽挥发油的量为0.80%,用GC/MS法从棉籽挥发油中分离并确定出16种化学成分。用峰面积归一化法通过化学工作站数据处理系统,得出各化学成分在挥发油中的质量分数。其中主要成分为:石竹烯量高达33.27%。     

大学实验教学中数据处理系统的开发和应用*

借助专业软件开发数据处理系统逐渐取代了传统的人工计算过程。以“化学海洋学实验”课程的数据自动处理为研究案例,介绍了数据处理系统的开发和应用过程。该系统的计算程序用R语言编写,用Java语言实现可视化,可以用实验数据快速得到最终结果并监测实验中间环节,简化了计算程序。教师可以及时检查学生实验数据的可靠性和准确性,有效地提高了教学效率。     

新解色谱现象

在客观分析色谱现象的基础上对色谱分离机理的传统解释提出了质疑和否定,并对色谱分离机理作出了新的解释。通过对色谱现象的研究和分析,不仅确定了一条流体运动的基本规律,还对固定相赋予了新的内涵,提出了能量场固定相的设想。由于对色谱分离原理进行了新的解释,因此对色谱现象提出了一个新的定义。     

高效液相色谱法测定葡萄酒中6种防霉剂的残留量

本文介绍了采用紫外、荧光双检测器,同时测定6种防霉剂的液相色谱法,该法操作简便,解决了多组分防霉剂不能同时测定以及回收率和灵敏度不高等问题。1　实验部分1.1　仪器与试剂　　Waters高效液相色谱仪(HPLC),配有紫外(UV)和荧光(FL)双检测器、双通道数据处理系统;Phenomenex固相萃取(SPE)仪。标准品为CHEMSERVICE提供;进口色谱纯甲醇;其他试剂为国产分析纯试剂。WatersSep packC18固相萃取柱(250mg;LOTNO.P4024A1)。1.2　样品溶液的制备　　标准溶液的配制精确称取一定量的多菌灵(carben dazine),加入少量的甲醇和2滴0 …     

多阶段线性程序升温毛细管气相色谱最佳分离温度的选择

本文提出了气相色谱程序升温分离已知样品的优化指标。在此基础上考虑到色谱柱温和样品组分在色谱柱内的路径差别对保留时间和分离度的影响。提出了气相色谱最佳多阶梯线性程序升温温度曲线选择的基本原则——“移动重叠分辨图”法,并用毛细管气相色谱实验对此进行了验证,理论值与实测值能很好吻合。     

低压离子色谱理论探讨

本文提出了低压离子色谱的设计思想,讨论了离子色谱分离柱的交换容量与分离检测之间的关系。同时对低压离子色谱的可行性进行了探讨,认为由于离子色谱柱填料的特殊性,低压在离子色谱这一领域是可行的。     

多组分光谱相关色谱及其在中药色谱指纺图谱分析中的应用

基于正交投影理论和相关色谱方法提出多组分光色谱方法提出多组分光谱相关 色谱。为克服联用色谱仪器的不等性噪声影响，采用目标组分投影前后的光谱夹角 余弦判据，判断不同的中药色谱指纹图谱的相关组分色谱峰簇。该方法为中药指纹 图谱的数据处理、合理评价以及中药谱效学的基本理论研究提供一种实用的工具。     

多组分光谱相关色谱及其在中药色谱指纺图谱分析中的应用

基于正交投影理论和相关色谱方法提出多组分光色谱方法提出多组分光谱相关 色谱。为克服联用色谱仪器的不等性噪声影响，采用目标组分投影前后的光谱夹角 余弦判据，判断不同的中药色谱指纹图谱的相关组分色谱峰簇。该方法为中药指纹 图谱的数据处理、合理评价以及中药谱效学的基本理论研究提供一种实用的工具。     

自然沉降法制备常压色谱柱

提出了自然沉降法制备常压色谱柱,它与传统方法制备的色谱柱相比,柱效和分离效果均有明显提高。此法装填的色谱柱还具有良好的稳定性和重复性。     

On-line multidimensional chromatography using packed capillary liquid chromatography and capillary gas chromatography

The introduction of selected fractions from a liquid chromatograph into a gas chromatograph has been described; however, analyses were performed by off-line experiments requiring collection and reinjection of the separate fractions or by on-line procedures where disadvantageously, only a fraction of the separated peak or a well resolved component in a mixture could be introduced into a gas chromatograph. This disadvantage is overcome by the apparatus and method described in this paper, which utilizes a multidimensional chromatography system employing a high efficiency, packed capillary LC column coupled on-line to a capillary gas chromatograph. The liquid chromatograph (so designed) can act as a highly efficient clean-up or chemical class fractionation step prior to introduction into the gas chromatograph, significantly reducing sample preparation times in many applications. Thus minor components in a complex matrix can be determined without prior sample clean-up, an example of which is the determination of polychlorinated biphenyls in a complex hydrocarbon matrix.     

Development and Practical Use of a High Performance Preparative Liquid Chromatographic System

The application of an analytical high performance liquid chromatograph to preparative tasks is discussed. Large capital Investments are the nom when purchasing modern high performance liquid chromatographic equipment. In many cases an analytical HPLC system can be made to du double duty by also serving as a preparative liquid chromatograph. Often, with a small additional capital Investment and minor equipment modifications a more versatile chromatograph is obtained. This paper will briefly review the process required to convert an analytical liquid chromatograph into a preparative liquid chromatograph. The resulting unit is fully automated and is capable of continuous unattended operation for periods of up to several weeks. Finally, the use of this system is illustrated by showing the scale up of a separation from an analytical to a preparative mode resulting in the isolation of high-purity standard materials.     

离子色谱的抑制系统及相关技术的发展

抑制系统是抑制型(双柱型)离子色谱系统极为重要的一个组成部分,也是离子色谱有别于其它类型的液相色谱的最重要特点之一。抑制器的发展经历了多个发展时期,而目前商品化的离子色谱仪亦分别采用不同形式的抑制手段。近年来,还发展了一些特殊的辅助抑制器,如接在抑制器后面CO2除去装置,用于提高被测离子的信号或进一步降低背景电导值。     

DX-2000I型离子色谱仪的改进

介绍DX－2000I型离子色谱仪改进的要点。改进后，该仪器具有DX－300型离子色谱仪的功能，能满足大亚湾核电站生产控制的需要。     

Tandem use of carboxypeptidase Y reactor and displacement chromatograph for peptide synthesis

A packed-bed enzyme reactor with immobilized carboxypeptidase Y was used in tandem with a displacement chromatograph for the preparation of N-benzoyl-L-arginyl-L-methioninamide, from N-benzoyl-L-arginine and L-methioninamide. The pumps and valves of the coupled enzyme reactor and displacement chromatograph were controlled by a microprocessor. The enzyme was immobilized on microparticulate amino-silica by glutaraldehyde and packed into a 60 X 4.6 mm I.D. column. The packed-bed reactor was used in the recirculating mode and components of the reaction mixture were subsequently separated by displacement chromatography on a 250 X 4.6 mm octadecyl-silica column using butoxyethoxyethanol as the displacer. Unreacted L-methioninamide was returned to the reaction mixture. Both the progress of the reaction and the extent of separation by displacement chromatography were monitored by high-performance liquid chromatographic analysis. The system was designed so that enzymatic peptide synthesis, separation by displacement chromatography, and column regeneration were carried out simultaneously by using two identical columns in parallel. An amount of 460 mg of N-benzoyl-L-arginyl-L-methioninamide having purity greater than 99% could be obtained in 24 h with this system. The tandem operation of the enzyme reactor and liquid chromatograph operated in the displacement mode offers a means for the synthesis and purification of peptides.     

气相色谱质谱联用仪与微机的数据传输和处理

报道了一种用于气相色谱质谱联用仪和微机之间实现数据传输和处理的方法。方法可更有效地利用质谱仪采集的数据，解决了工作站处理数据的局限性。经数据格式转换，原始数据可以在微机上实现色谱峰再现，从而为色谱条件的优化和定量数据处理创造了条件。     

Scale-down of continuous protein purification by annular chromatography. Design parameters for the smallest unit

Theoretically, in fixed-bed chromatography an infinite separation time or volume is available. In annular chromatography the separation time is limited by the time required for a single rotation. In a chromatograph with a smaller annulus than the theoretical one, the equilibration zone will overtake the feed zone. The required separation time is determined by a number of steps such as equilibration, loading, washing, elution, regeneration and the retention of the solute. A mathematical model has been developed to estimate the minimum radius of an annular chromatograph. The minimal geometry of an annular chromatograph was calculated for a model system immunoglobulin and bovine serum albumin.     

On-line analysis of products from hydrogenation of carbon monoxide by capillary gas chromatography with thermal conductivity detection

A combination of thermal conductivity detectors with capillary columns is used for on-line analysis of the products from a micropolit plant for the study of carbon monoxide hydrogenation. The system includes an automatically operated heated tenport sampling valve, a HP-5890-A gas chromatograph fitted with two capillary columns and thermal conductivity detectors, and a logging/controlling system. The single column design means that two analyses can be done simultaneously in one chromatograph and offers high versatility with the possibility of combining different capillary columns to cope with the needs of variable process conditions and catalyst selectivities.     

Characterization of Polyethylene Using Fast Analytical Temperature Rising Elution Fractionation with Triple Detection (ATREF 3D)

A commercially available gel permeation chromatograph with triple detection (GPC3D) was coupled with a gas chromatograph to obtain a fast analytical temperature rising fractionation system with triple detection (ATREF3D). On this hybrid instrument we developed a fast method for evaluating in one run, and with less than 0.5 mg of sample, the density, molecular weight, and the type of polyethylene. The method was evaluated with excellent results on commercial polyethylene resins typically used for film and packaging applications.     

Operation of an Improved,Continuous Annular Chromatograph

Abstract

A rotating annular chromatograph has been demonstrated to have utility in the continuous separation of solutes in a feed stream. Recent modifications to the system have resulted in a more efficient separation. Design of the inlet and the exit has been significantly changed to improve chromatograph performance. Refinements have also been made to the method of gradient elution. The effects of changing superficial velocity and initial resin loading on the height equivalent to a theoretical plate are shown for the ternary nickel-cobalt carbonate amine system. A continuous separation of this ternary mixture utilizing pH gradient elution is presented.