On-line introduction of high-pressure gas-liquid sample for capillary gas chromatographic analysis

An on-line sample introduction technique in capillary gas chromatograph (CGC) for the analysis of high-pressure gas-liquid mixtures has been designed and evaluated. A sample loop of 0.05 muL and a washing solvent loop of 0.5 muL are mounted on a 10-port switching valve, which serves as the injection valve. A capillary resistor was connected to the vent of sample loop in order to maintain the pressure of the sample. Both the sample and the washing solvent are transferred into the split-injection port through a narrow bore fused silica capillary inserted into the injection liner through a septum. The volume of the liner is used both as the pressure-release damper and evaporation chamber of the sample. On-line analysis of both reactants and resultants in ethylene olimer reaction mixture at 5 MPa was carried out, which demonstrated the applicability of the technique. (C) 2004 Elsevier B.V. All rights reserved.

A gas chromatographic analysis of light hydrocarbons on a column packed with modified silica gel

A one-meter long column packed with silica gel is used to separate light hydrocarbons. The silica gel has been modified with several kinds of gas chromatography stationary phases. Among these, PEG 2000 shows fairly good effect when using 80-100 meshes silica gel for the separation of mixture of methane, ethane, ethylene, acetylene, propane, propylene and n-, i-butane. The different behavior of silica gel between batch to batch is also found. When silica gel is coated with a small amount of Al2O3 prepared with sol-gel method, better resolution has been observed on a 2-meter column compared with the non-modified silica gel.

水菖蒲的化学成分研究和忍冬属植物的色谱分析

本论文由三章组成。第一章阐述了藏药水菖蒲的化学成分研究，共分离鉴定了39个化学成分，其中6个为新化合物。第二章报道了几种忍冬属植物的HPLC、HPLC-MS、GC分析以及抑菌活性、重金属含量测定结果。第三章概述了菖蒲属植物的研究进展。 第一章报道了水菖蒲(Acorus calamus L.)化学成分的分离纯化与结构鉴定。采用正、反相硅胶柱层析等分离方法，从水菖蒲的根中共分离出41个化合物，通过红外、质谱、核磁共振及X-ray单晶衍射等波谱方法和模拟计算方法鉴定了其中39个化合物的结构，主要为倍半萜、苯丙素、甾体类化合物。其中含有5个新的倍半萜类化合物和1系列新的甾体皂苷衍生物。经波谱分析将它们的结构鉴定为 1b, 7a(H)-cadinane-4a, 6a, 10a-triol (1), (2R,6R,7S,9S)-1(10), 4-cadinadiene-2, 9-diol (2), 1a, 5b-guaiane-10a-O-ethyl-4b, 6b-diol (7), 6b, 7b(H)-cadinane-1a, 4a, 10a-triol (13)，(1R,4R,6S,10R)-1-hydroxy-7(11)-cadinen-5, 8-dione (14)， 4′-O-正n碳酰基-3-O- β-D-葡萄糖基谷甾醇(n=14, 16, 18, 22) (15)。 第二章包括四个部分。第一部分报道了忍冬属三种植物40个样品的HPLC测定和对主要活性成分绿原酸的定量分析结果，以及运用HPLC-MS技术对色谱图中8个峰进行指认。在此基础上，考察了种植和采收多个因素对绿原酸含量的影响。第二部分报道了忍冬属三种植物27个样品的GC分析，根据样品的挥发性成分的保留时间对不同样品进行了定性比较，并考察了花期及海拔高度对植物挥发性成分的影响。第三、四部分分别阐述了灰毡毛忍冬和红腺忍冬的体外抑菌活性研究和重金属含量测定结果。 第三章全面系统地概述了菖蒲属植物的化学成分和药理活性研究进展。 This dissertation is composed by three chapters. The first chapter elaborates the phytochemical investigation of Acorus calamus L. Thirty-nine compounds including six new compounds were isolated and identified. The second chapter reports the research on genus Lonicera by HPLC, HPLC-MS and GC. Antifungal activity and heavy metals measurement of genus Lonicera were reported. The third chapter is a review about the research progress on the plant family of Acorus. The first chapter focuses on the isolation and identification of chemical constituents from Acorus calamus L.. Forty-one compounds were isolated from the root of Acorus calamus L. by repeat column chromatography over normal and reversed phase silica gel, the structure of thirty-nine compounds was identified by spectroscopic methods and computational methods, including IR, MS, NMR and X-ray. Those compounds mainly belonged to sesquiterpene, phenylpropanoid and steroid. Among them, five are new sesquiterpenes and one series are new steroid glycoside derivatives. Their structure were suggested as 1b, 7a(H)-cadinane-4a, 6a, 10a-triol (1), (2R,6R,7S,9S)-1(10), 4-cadinadiene-2, 9-diol (2), 1a, 5b-guaiane-10a-O-ethyl-4b, 6b- diol (7), 6b, 7b(H)-cadinane-1a, 4a, 10a-triol (13), (1R,4R,6S,10R)-1-hydroxy-7(11)- cadinen-5, 8-dione (14), 4′-O-carbonyl-3-O-β-D-glucosyl-sitosterol (carbonyl = tetradecanoyl, hexadecanoyl, octadecyl, docosanoyl) (15). The second chapter consists of four parts. The first part reports the HPLC analysis of forty samples of the genus Lonicera, and the quantitative investigation of chlorogenic acid in these samples by HPLC analysis. Relationship between the content of chlorogenic acid in different samples and their planting conditions and harvesting time were discussed. Furthermore, eight compounds were identified or tentatively characterized based on their mass spectra and UV spectra profiles. The second part is about qualitative analysis of the volatile constituent in twenty-seven samples of genus Lonicera by GC. The effect of planting altitude and harvesting time on the volatile constituent was also investigated. The third and fourth parts describe the antifungal activity and content of some kinds of heavy metals of L. macranthoides Hand.-Mazz. and L. hypoglauca Miq.. The third chaspter is a review about the research progress of the plant family of Acorus.

Effect of La3+ on structure and electrochemical reaction of microperoxidase-11 in imitated physiological solution

In this paper, the interaction mechanism between La3+ and microperoxidase-11 (MP-11) in the imitated physiological solution was investigated with the electrochemical and spectroscopic methods. It was found that when the molar ratio of La3+, and MP-11 is low, such as 2, La3+ can coordinate with oxygen in the propionic acid group of the heme group in the MP-11 molecule, forming the La-MP-11 complexes and leading to the increase in the non-planarity of the porphyrin cycle in the heme group and then the increase in the extent of exposure of the electrochemically active center, Fe(I I I) in the porphyrin cycle of the heme group. The increase in the extent of exposure of the electrochemically active center, Fe(III) in the porphyrin cycle of the heme group would increase the reversibility of the electrochemical reaction of the La-MP-11 complexes and its electrocatalytic activity for the reduction of H2O2. The results of the chromatographic analysis demonstrated that the average molar ratio of La3+ and MP-11 in the La-MP-11 complexes is 1.62.When the molar ratio of La3+ and MP-11 is high, such as 3, La3+ would shear some amino acid residues of the peptide of MP-11. Therefore, many La3+ ions can bind to the oxygen- and/or nitrogen-containing groups in the sheared amino acid residues except coordinating with the sheared and non-sheared MP-11 molecules.

生物－热催化过渡带沉积成岩演化及其成烃作用研究

The biothermocatalytic transitional zone gas is a new type of natural gas genetic theory, and also an clean, effective and high quality energy with shallow burial depth, wide distribution and few investment. Meanwhile, this puts biothermocatalytic transitional zone gas in important position to the energy resource and it is a challenging front study project. This paper introduces the concept, the present situation of study and developmental trend about biothermocatalytic transitional zone gas in detail. Then by using heat simulating of source rocks and catalysis mechanism analysis in the laboratory and studying structural evolution, sedimentation, diagenesis and the conditions of accumulation formation and so on, this paper also discusses catalytic mechanism and evolutionary model of the biothermocatalytic transitional zone gas formation, and establishes the methods of appraisal parameter and resources prediction about the biothermocatalytic transitional zone gas. At last, it shows that geochemical characteristics and differentiated mark of the biothermocatalytic transitional zone gas, and perfect natural gas genetic theory, and points out the conditions of accumulation formation, distribution characteristics and potential distribution region on the biothermocatalytic transitional zone gas m China. The paper mainly focuses on the formation mechanism and the resources potential about the biothermocatalytic transitional zone gas. Based on filed work, it is attached importance to a combination of macroscopic and microcosmic analysis, and the firsthand data are obtained to build up framework and model of the study by applying geologic theory. Based on sedimentary structure, it is expounded that structural actions have an effect on filling space and developmental cource of sediments and evolution of source rocks. Carried out sedimentary environment, sequence stratigraphy, sedimentary system and diagenesis and so on, it is concluded that diagenesis influences developmental evolution of source rocks, and basic geologic conditions of the biothermocatalytic transitional zone gas. Applying experiment simulating and catalytic simulating as well as chemical analysis, catalytic mechanism of clay minerals is discussed. Combined diagenecic dynamics with isotope fractionation dynamics, it is established that basis and method of resource appraisal about the biothermocatalytic transitional zone gas. All these results effectively assess and predict oil&gas resources about the biothermocatalytic transitional zone gas-bearing typical basin in China. I read more than 170 volumes on the biothermocatalytic transitional zone gas and complete the dissertation' summary with some 2.4 ten thousand words, draw up study contents in some detail and set up feasible experimental method and technologic course. 160 pieces of samples are obtained in oilfield such as Liaohe, Shengli, Dagang and Subei and so on, some 86 natural gas samples and more than 30 crude oil samples. Core profiles about 12 wells were observed and some 300 geologic photos were taken. Six papers were published in the center academic journal at home and abroad. Collected samples were analysised more than 1000 times, at last I complete this dissertation with more than 8 ten thousand words, and with 40 figures and 4 plates. According to these studies, it is concluded the following results and understandings. 1. The study indicates structural evolution and action of sedimentary basin influence and control the formation and accumulation the biothermocatalytic transitional zone gas. Then, the structural action can not only control accommodation space of sediments and the origin, migration and accumulation of hydrocarbon matters, but also can supply the origin of energy for hygrocarbon matters foramtion. 2. Sedimentary environments of the biothermocatalytic transitional zone gas are lake, river and swamp delta- alluvial fan sedimentary systems, having a warm, hot and humid climate. Fluctuation of lake level is from low to high., frequency, and piling rate of sedimentary center is high, which reflect a stable depression and rapidly filling sedimentary course, then resulting in source rocks with organic matter. 3. The paper perfects the natural gas genetic theory which is compound and continuous. It expounds the biothermocatalytic transitional zone gas is a special gas formation stage in continuous evolutionary sequence of organic matter, whose exogenic force is temperture and catalysis of clay minerals, at the same time, having decarbxylation, deamination and so on. 4. The methodology is established which is a combination of SEM, TEM and Engery spectrum analysis to identify microstructure of crystal morphology about clay minerals. Using differential thermal-chromatographic analysis, it can understand that hydrocarbon formation potential of different typies kerogens and catalytic method of all kinds of mineral matrix, and improve the surface acidity technology of clay minerals measured by the pyridine analytic method. 5. The experiments confirm catalysis of clay minerals to organic matter hygrocarbon formation. At low temperature (<300 ℃), there is mainly catalysis of montmorillonite, which can improve 2-3 times about produced gas of organic matters and the pyrolyzed temperature decreased 50 ℃; while at the high temperature, there is mainly catalysis of illite which can improve more than 2 times about produced gas of organic matters. 6. It is established the function relationship between organic matter (reactant) concentration and temperature, pressure, time, water and so on, that is C=f (D, t). Using Rali isotope fractionation effect to get methane isotope fractionation formula. According to the relationship between isotope fractionation of diagenesis and depth, and combined with sedimentary rate of the region, it is estimated that relict gas of the biothermocatalytic transitional zone gas in the representative basin. 7. It is revealed that hydrocarbon formation mechanism of the biothermocatalytic transitional zone gas is mainly from montmorillonite to mixed minerals during diagenesis. In interlayer, a lot of Al~(3+) substitute for Si~(4+), resulting in a imbalance between surface charge and interlayer charge of clay minerals and the occurrence of the Lewis and Bronsted acid sites, which promote to form the carbon cation. The cation can form alkene or small carbon cation. 8. It is addressed the comprehensive identification mark of the biothermo - catalytic transitional zone gas. In the temproal-spatial' distribution, its source rocks is mainly Palaeogene, secondly Cretaceous and Jurassic of Mesozoic, Triassic, having mudy rocks and coal-rich, their organic carbon being 0.2% and 0.4% respectively. The vitrinite reflection factor in source rocks Ro is 0.3-0.65%, a few up to 0.2%. The burial depth is 1000-3000m, being characterized by emerge of itself, reservoir of itself, shallow burial depth. In the transitional zone, from shallow to deep, contents of montmorillonites are progressively reduced while contents of illites increasing. Under SEM, it is observed that montmorillonites change into illite.s, firstly being mixed illite/ montmorillonite with burr-like, then itlite with silk-like. Carbon isotope of methane in the biothermocatatytic transitional zone gas , namely δ~(13)C_1-45‰- -60 ‰. 9. From the evolutionary sequence of time, distribution of the biothermocatalytic transitional zone gas is mainly oil&gas bearing basin in the Mesozoic-Neozoic Era. From the distribution region, it is mainly eastern stuctural active region and three large depressions in Bohaiwang basin. But most of them are located in evolutionary stage of the transitional zone, having the better relationship between produced, reservoir and seal layers, which is favorable about forming the biothermocatalytic transitional zone gas reservoir, and finding large gas (oil) field.

The optimization of high performance liquid chromatographic method for analysis of trace microcystins in natural water bodies

The ratio of methanol., water and trifluoroacetic acid ( TFA) was regulated to change the polarity and the pH of the rinse solution and the eluent, so as to improve the high performance liquid chromatography HPLC) detection method for trace microcystines (MCs) in natural water bodies. The results showed that 40 % similar to 45 % methanol-water solution containing 0. 1 % TFA could get good effects on the rinse of impurity, and 70% methanol-water solution containing 0. 1% TFA could elute all the MCs in solid phase extraction ( SPE) cartridge ( C-18), In this way. it is suggested that, in analysis of environmental samples with high concentration of impurity, impurity should be washed with 40% similar to 45% methanol-water solution containing 0. 1% TFA, and MCs should be eluted with 70% similar to 100% methanol-water solution containing 0. 1% TFA.

Capillary liquid chromatographic-high-resolution mass spectrometric analysis of ribonucleotides

A method of capillary HPLC-high-resolution MS was developed for the trace analysis of ATP, GTP, dATP and dGTP Dimethylhexylamine (DMHA) was used as ion-pairing agent for the HPLC retention and separation of the nucleotides and positive ion electrospray time-of-flight MS was used for the detection. The application of capillary HPLC allowed minimal usage of DMHA while providing excellent peak retention and resolution, which significantly reduced the ion suppression in electrospray ionization-MS analysis and thus increased the sensitivity. Adduct ions of nucleotides and DMHA were used as quantitative ions in order to achieve the best sensitivity. DMHA concentration at 5 mM in the aqueous mobile phase at pH 7 was found to be the optimal conditions for the C Is capillary column. The method was applied to determine ATP level in cultured C6 glioma cells that were treated with toxic concentrations of Zn. The results showed that the cellular ATP level decreased from 2.7 pmol/cell (<10% cell death) in average control cell samples to 0.36 pmol/cell as the concentration of Zn increased to 120 mg/l (>35% cell death) in culture medium.

Correlation analysis of the structures and gas-liquid chromatographic retention indices of amines

Quantitative structure-retention relationship(QSRR) was studied for amines to gas-liquid chromatography on three stationary phases of different polarities with the topological indices A(m) (A(m1), A(m2), A(m3)) and gravitational index GI. The algorithm of "Leaps and Bounds" was performed for selection of the variables. And the multi-regression and the quasi-Newton neural networks were employed for the calculation with better results.

CORRELATION-ANALYSIS IN STRUCTURE AND CHROMATOGRAPHIC DATA OF ORGANOPHOSPHORUS COMPOUNDS BY GAI

This approach is undertaken to examine the correlation ability of the general a(N)-index (GAI) to predict chromatographic behavior. The test is performed on various types of organophosphorus compounds. The results demonstrate that the GAI possesses a good correlation with chromatographic properties.

Evaluation of nonlinear chromatographic performance by frontal analysis using a simple multi-plate mathematical model

A multi-plate (NIP) mathematical model was proposed by frontal analysis to evaluate nonlinear chromatographic performance. One of its advantages is that the parameters may be easily calculated from experimental data. Moreover, there is a good correlation between it and the equilibrium-dispersive (E-D) or Thomas models. This shows that it can well accommodate both types of band broadening that is comprised of either diffusion-dominated processes or kinetic sorption processes. The MP model can well describe experimental breakthrough curves that were obtained from membrane affinity chromatography and column reversed-phase liquid chromatography. Furthermore, the coefficients of mass transfer may be calculated according to the relationship between the MP model and the E-D or Thomas models. (C) 2004 Elsevier B.V. All rights reserved.