毛细管多维气相色谱法分析炼厂气

用ＨＰ６８９０气相色谱仪,使用多孔层空心毛细管柱（ＰＬＯＴ）,选用ＨＰ－ＰＬＯＴ／Ｐｏｒａｐａｃｋ Ｑ色谱柱测定ＣＯ２;ＨＰ－ＰＬＯＴ ５Ａ分子筛柱测定Ｏ２,Ｎ２,ＣＨ４;ＨＰ－ＰＬＯＴ／Ａｌ２Ｏ３柱测定有机烃类。采用３阀４柱色谱运行系统,用ＦＩＤ及ＴＣＤ分别检测烃类及无机气体组分。用色谱工作站控制气动切换阀切换气样走向及两种检测器数据的转换校正和归一化定量计算,用已知物对照法定性,测定了炼厂气中     

新型碳分子筛毛细管色谱柱

新型碳分子筛毛细管色谱柱中国科学院兰州化学物理研究所色谱技术研究开发中心研究人员经过两年多的探索，成功地研制开发出碳分子筛石英毛细管气相色谱柱。经修饰改性的碳分子筛Ｃ－２０００色谱柱能够一次进行分离Ｈ２、Ｏ２、Ｎ２、ＣＯ、ＣＨ４、ＣＯ２、Ｃ２Ｈ２、Ｃ...     

新型碳分子筛毛细管色谱柱

新型碳分子筛毛细管色谱柱中国科学院兰州化学物理研究所色谱技术研究开发中心研究人员经过两年多的探索，成功地研制开发出碳分子筛石英毛细管气相色谱柱。经修饰改性的碳分子筛Ｃ－２０００色谱柱能够一次进行分离Ｈ２、Ｃ２、Ｎ２、ＣＯ、ＣＨ４、ＣＯ２、Ｃ２Ｈ２、Ｃ...     

新型碳分子筛毛细管色谱柱

中国科学院兰州化学物理研究所色谱技术研究开发中心研究人员经过两年多的探索，成功地研制开发出碳分子筛石英毛细管气相色谱柱。经修饰改性的碳分子筛Ｃ－２０００色谱柱能够一次进行分离Ｈ２、Ｏ２、Ｎ２、ＣＯ、ＣＨ４、ＣＯ２、Ｃ２Ｈ２、Ｃ２Ｈ４、Ｃ２Ｈ６等九种组...     

反相离子对色谱法测定硫代硫酸根和碘离子的研究

 首次利用Ｓ２Ｏ２－３和Ｉ－与Ｈｇ－ＥＤＴＡ二元络合物通过柱前衍生形成ＥＤＴＡ－Ｈｇ－Ｓ２Ｏ３和ＥＤＴＡ－Ｈｇ－Ｉ两种三元络合物的方法，实现了对Ｓ２Ｏ２－３和Ｉ－的间接反相离子对色谱分离和紫外检测。在ＺｏｒｂａｘＯＤＳ柱上，用甲醇∶水＝２３∶７７作流动相，内含对离子ＴＢＡ＋３．０ｍｍｏｌ／Ｌ，ＥＤＴＡ１．０ｍｍｏｌ／Ｌ，ＮａＮＯ３２．０ｍｍｏｌ／Ｌ和缓冲剂ＫＨ２ＰＯ４－Ｎａ２ＨＰＯ４（ｐＨ７．０），紫外２５４ｎｍ检测。Ｓ２Ｏ２－３和Ｉ－的最小检出限分别为６１．１ｎｇ和３７．６ｎｇ。方法简便，选择性好。     

超氧化物歧化酶与过氧化氢酶的缀合物的制备与性质研究

我们用戊二醛制备了超氧化物歧化酶（ＳＯＤ）和过氧化氢酶（ＣＡＴ）的缀合物，ＳＯＤ和ＣＡＴ都是抗氧化应激酶系的成员，缀合物兼具两个酶的功能，具有很强的Ｈ＿２Ｏ＿２抑制作用，从而能更有效地清除活性氧，使之更适合于医用。     

水溶性铱膦配合物催化苯乙烯加氢反应研究

合成了两种水溶性铱膦配合物，ＩｒＣｌ（ＣＯ）－（ＴＰＰＴＳＷ）２和ＨＩｒＣｌ２（ＣＯ）（ＴＰＰＴＳ）２「ＴＰＰＴＳ＝Ｐ（ｍ－Ｃ６Ｈ４ＳＯ４Ｎａ）３」，并且在两相催化反应体系中评价了它们对苯乙烯加氢活性，考察了反应温度，压力，两种相转移试剂ＣＣＴＡＢ和β－ＣＤ浓度变化对苯乙烯加氢转化率的影响。     

碱性探针分子在固体超强酸上的程序升温脱附研究

采用ＴＣＤ和ＦＩＤ色谱检测器，对固体超强酸上吡啶、苯和甲苯的程序升温脱附过程进行了研究，并对液氮温度下收集的脱附产物进行了色谱－质谱分析，结果表明，吡啶、苯和甲苯等探针分子在固体超强酸上发生氧化反应，生成ＣＯ２和ＳＯ２，程序升温脱附数据与样品的酸性和正丁烷异构化反应活性之间并无对应关系。     

纳米尖晶石型Co2MnO4的形成过程及其F-T反应性能

用溶胶凝胶法制备了尖晶石型Ｃｏ２ＭｎＯ４超细粒子，用ＤＴＡＴＧ，ＸＲＤ，ＴＥＭ，ＦＴＩＲ等手段研究了Ｃｏ２ＭｎＯ４超细粒子的形成过程，进而用反应评价结合ＸＲＤ，ＸＰＳ，ＢＥＴ比表面积测试研究了Ｃｏ２ＭｎＯ４催化剂的比表面积和表面结构与其ＦＴ反应性能间的关系．结果表明，Ｃｏ２ＭｎＯ４超细粒子可以在较低温度（２５０～３５０℃）下形成，并具有粒度小，分布均匀等特点．用该法制备的超细粒子Ｃｏ２ＭｎＯ４，其催化活性明显优于相同组成的大颗粒催化剂．     

Gd（ClO_4）_3·3H_2O－18C6－CH_3CN三元体系25℃相平衡研究及配合物的合成与表征

采用半微量相平衡方法研究了Ｇｄ（ＣｌＯ_４）_３·３Ｈ_２Ｏ－１８Ｃ６－ＣＨ_３ＣＮ三元体系在２５℃时的溶解度，测定了饱和溶液的折光率。结果表明，该体系在２５℃时形成两种化学计量的配合物，其组成分别为：Ｇｄ（ＣｌＯ_４）_３·１８Ｃ６·３Ｈ_２Ｏ·２ＣＨ_３ＣＮ和Ｇｄ（ＣｌＯ_４）_３·２（１８Ｃ６）·３Ｈ_２Ｏ·２ＣＨ_３ＣＮ，制备了固态配合物，用化学分析及元素分析、ＩＲ、ＤＴＧ、ＴＧ及ＤＳＣ等研究了配合物的组成与性质。     

Enantiomeric separation and quantification of ephedrine-type alkaloids in herbal materials by comprehensive two-dimensional gas chromatography

The separation of ephedrine-type alkaloids and their enantiomers in raw herbs and commercial herbal products was investigated by carrying out enantioselective separation in the first-dimension column (containing beta-cyclodextrin as the chiral selector) of a comprehensive two-dimensional gas chromatography (GC x GC) system, whereas a polar polyethylene glycol capillary column was used for separation in the second dimension. Naturally occurring ephedrine-type alkaloids and their synthetic analogues (enantiomeric counterparts) were adequately resolved from each other, as well as from potential interference species in the sample matrix using GC x GC, whereas single column GC analysis was unable to separate all the alkaloids of interest. Detection limits in the order of 0.1-1.3 microg/mL and linearity of calibration with R(2)>or=0.999 over approximately the range of 0.5-100 microg/mL for the quantitative determination of various ephedrine-type alkaloids were obtained. The commercial herbal products tested contained mostly (-)-ephedrine, (+)-pseudoephedrine, (-)-N-methylephedrine and (-)-norephedrine, with concentrations in the range of 40-2100, 0-1,300, 15-300 and 0-30 microg/g of the product, respectively, and repeatability of analysis was generally in the range of 1-5%. The present GCxGC method is effective and useful for the determination of the dosage levels of the principle ephedrine-type alkaloids in commercial health supplements and complex raw herb formulations, as well the differentiation of ephedrine-containing products that were derived from natural plant or synthetic sources, e.g., simply by visualizing the presence or absence of the enantiomeric pairs of (+/-) ephedrine and (+/-)-N-methylephedrine in the GC x GC chromatograms.     

Rapeseed oil methyl ester pyrolysis: on-line product analysis using comprehensive two-dimensional gas chromatography

Thermochemical conversion processes play a crucial role in all routes from fossil and renewable resources to base chemicals, fuels and energy. Hence, a fundamental understanding of these chemical processes can help to resolve the upcoming challenges of our society. A bench scale pyrolysis set-up has been used to study the thermochemical conversion of rapeseed oil methyl ester (RME), i.e. a mixture of fatty acid methyl esters. A GC×GC, equipped with both a flame ionization detector (FID) and a time-of-flight mass spectrometer (TOF-MS), allows quantitative and qualitative characterization of the reactor feed and product. Analysis of the latter is accomplished using a dedicated high temperature on-line sampling system. Temperature programmed analysis, starting at -40°C, permits effluent characterization from methane up to lignoceric acid methyl ester (C(25)H(50)O(2)), in a single run of the GC×GC. The latter combines a 100% dimethylpolysiloxane primary column with a 50% phenyl polysilphenylene-siloxane secondary column. Modulation is started when the oven temperature reaches 40°C, thus dividing the chromatogram in a conventional 1D and a comprehensive 2D part. The proposed quantification approach allows to combine the quantitative GC×GC analysis with 2 other on-line 1D GC analyses, resulting in a complete and detailed product composition including the measurement of CO, CO(2), formaldehyde and water. The GC×GC reveals that the product stream contains a huge variety of valuable products, such as linear alpha olefins, unsaturated esters and aromatics, that could not have been identified and quantified accurately with conventional 1D GC because of peak overlap.     

玻璃芯毛细管柱的研制

介绍了含玻璃内芯的新型毛细管色谱柱的制备方法,以正癸烷和正庚烷为测试物,测定了这种柱子的柱效率和柱容量,并与普通玻璃毛细管柱进行了比较。结果表明,所制玻璃芯毛细管柱的柱效率和柱容量均优于普通毛细管柱。用玻璃芯毛细管柱及使用这种柱子的GC/FTIR联用系统分别分析了烷芳烃混合物和合成汽油样品,取得了满意的结果。     

变径毛细管柱GC／FTIR联用技术的研究

本文介绍了使用新型变径毛细管柱的气相色谱/傅里叶变换红外光谱联用技术(GC/FTIR)。以正构烷烃的混合物为样品,研究了载气速流、色谱进样量及柱后死体积对联用效果的影响。分别在变径毛细管柱GC/FTIR和普通毛细管柱GC/FTIR联用系统上分析了烷烃芳烃混合物和合成汽油样品,并利用软件系统提供的程序和红外标准谱库对所得光谱进行了检索。实验结果表明,变径毛细管柱GC/FTIR系统具有色谱进样量大,可鉴定组分多,分离能力强和检测灵敏度高等显著优点。     

硅烷化衍生-气相色谱-质谱联用法测定橙汁粉中维生素C

橙汁粉样品用N,N-二甲基甲酰胺提取,并离心分离,所得上清液中抗坏血酸与六甲基二硅氨烷和三甲基氯硅烷进行衍生反应,产物用正庚烷萃取。萃取液加入棕榈酸甲酯作为内标,供气相色谱-质谱分析。在气相色谱分离中用HP-5MS毛细管柱(30 m×250μm,0.25μm)为固定相,在质谱测定中采用全扫描模式。硅烷化抗坏血酸标准与内标峰面积的比值与硅烷化抗坏血酸的质量在1.0～5.0 mg范围内呈线性关系。方法用于橙汁粉样品中维生素C的测定,橙汁粉中维生素C的平均质量分数(n=6)为0.195 4%,回收率在92.3%～98.5%之间。     

Fast gas chromatography: packed column solvating gas chromatography versus open tubular column gas chromatography

Packed capillary column solvating gas chromatography (SGC) and open tubular column gas chromatography (GC) were compared with respect to their potentials for fast separations. A recently introduced "universal" peak capacity equation was used to compare the performance of these two methods. The effects of various factors on peak capacity were investigated. Results demonstrate that retention factor and column efficiency are the main factors affecting peak capacity for fast separations. Packed columns produce both high retention factors and high selectivities. While high efficiencies and high peak capacities can be demonstrated by both techniques, open tubular column GC can surpass packed capillary column SGC in both measurements, except for the case of the analysis of simple mixtures in short analysis times, where retention factor and selectivity become important. Practical aspects such as pressure drop and sample capacity are compared for SGC and open tubular column GC. It was found that packed column SGC demonstrates higher sample capacities, but requires much higher column inlet pressures than open tubular column GC. A variety of mobile phases can be used for packed column SGC, which can provide high solvating power for large and polar compounds.     

Effects of pressure drop on absolute retention matching in comprehensive two-dimensional gas chromatography

Comprehensive two-dimensional gas chromatography (GC x GC) analysis has the capability to resolve many more components of complex mixtures than traditional single column GC analysis. There is an increasing need to provide reliable identification of these separated components; time-of-flight mass spectrometry (TOFMS) is the most appropriate technology to achieve this task. Rather than require MS for all GC x GC separations, it is desirable to assign peak identities to specific peak positions in the GC x GC separation space, and this necessitates matching peak retentions in the two experiments - GC x GC-FID and GC x GC-TOFMS. The atmospheric vs. vacuum outlet conditions confound this task. It is shown here that by employing a supplementary gas supply, provided to a T-union between the column outlet and the MS interface, it is possible to generate 2D chromatograms for GC x GC-FID and GC x GC-TOFMS that are essentially exactly matched. There is no degradation in separation performance or efficiency in the second column in the system interfaced to the T-union. Since the GC x GC-FID experiment uses hydrogen for maximum efficiency, and GC x GC-TOFMS uses helium carrier, translation of (conditions/retentions) must account for the different viscosities of the carrier gases. Translation of conditions is based on well-known principles established in single column analysis. Tabulated data illustrate that retention reproducibility was of the order of better than 4 s for the average first dimension retention difference, and about 40 ms for the average second dimension retention difference when comparing GC x GC-FID and GC x GC-TOFMS results. This should provide considerable support for identification in routine GC x GC-FID analysis of specific sample types, once the peaks in 2D separation space have been assigned identities through GC x GC-TOFMS analysis.     

GC/MS分析羰基化产物萘普生甲酯

 α－（6-甲氧基-2-萘基）-乙醇在催化剂的作用下,与甲醇和CO发生羰基化反应,一步生成α－（6-甲氧基-2-萘基）丙酸甲酯（萘晋生申酯）。应用气相色谱-质谱联用技术,对这个反应过程中生成的各种化合物进行了分析,获得两个中间产物6-甲氧基萘乙烯和1-甲氧基-1-（6'-甲氧基-2'-萘基）乙烷的GC／MS数据资料,为推测该催化反应机理提供了可靠的依据。     

Comprehensive two-dimensional gas chromatography in the analysis of dietary fatty acids

Comprehensive two-dimensional gas chromatography utilising a semi-rotating cryogenic modulator was applied to the analysis of dietary milk derived fatty acids. Four column combinations were tested: two polar-nonpolar and two different nonpolarpolar column combinations. Best results were obtained with a nonpolar-polar column set, with narrow-bore (50 microm ID) Carbowax column as the second column. The GC x GC method clearly improved the separation efficiency of the fatty acids in comparison with one-dimensional GC analysis and proved to be suitable for the quantification of the analytes. The relative standard deviations (RSD) of the retention times in the first and second dimensions were on average 0.06% and 4.9%, respectively. The relative RSD for peak volumes was on average 2.9%.     

羧甲基牛膝多糖的制备、结构及生物活性研究

在NaOH水溶液中，以ClCH_2COOH为羧甲基化试剂，对牛膝多糖(AbPS)进行了羧 甲基化，粗产物经DEAE-Cellulose及Sephadex G-25两次柱层析纯化，得到羧甲基 牛膝多糖(CM-AbPS)纯品，经高效液相法（HPLC）及毛细管电泳法（CE）检测表明 具有较好的均一性，并通过样品甲基化和GC-MS分析，对羧甲基牛膝多糖链中羧甲 基的分布进行了研究，结果表明羧甲基牛膝多糖中羧甲基主要取代的糖链中呋喃果 糖的4-位上。该产物具有抗肿瘤活性。