真空熔融气相色谱法测定固体中痕量氩气的研究

建立了用气相色谱法测定固体内部痕量惰性气体的新方法.有效地解决了处于低真空状态待测气样的给样问题,优化了样品气体的纯化条件.用多种基准物质绘制了不同柱长的校正曲线,证明了新方法的可靠性.     

离子色谱法在氢燃料电池汽车用氢气中的应用现状及展望

氢燃料电池汽车用氢气中痕量杂质会影响氢燃料电池的性能,国内外标准均严格规定了痕量杂质的限值要求。离子色谱法（IC） 具有操作简单、分析快速、灵敏度高、选择性好、可多组分检测的特点,ISO 14687－2∶2012、SAE J2719∶2015和GB/T 37244－2018等标准均涉及到离子色谱法分析其中的部分指标。目前离子色谱法在环境空气、固定污染源废气、天然气、烟气等气体分析领域有广泛应用,在氢燃料杂质的分析领域尚在起步阶段。该文综述了氢燃料和其他气体分析领域中总卤化物、甲酸、氨和总硫化物的分析方法,将离子色谱与不同分析技术进行比较。并基于离子色谱在其他气体杂质分析领域的应用进展,对其在氢燃料电池汽车用氢气杂质分析中的应用作出展望。     

离子色谱法测定气体中痕量二氧化硫

建立了测定气体中痕量二氧化硫的离子色谱法。采用氢氧化钠–过氧化氢溶液为吸收液,将气体样品中痕量二氧化硫转化为硫酸根离子,以离子色谱法测定硫酸根离子,从而得到气体中二氧化硫含量。二氧化硫气体含量在1~100μL/L范围内与色谱峰面积线性关系良好,相关系数为0.999 9。二氧化硫的检出限为0.1μg/L,测量结果的重复性小于2%(n=6),测定标准样品的回收率在98.1%~99.6%之间,准确度优于对照方法。     

电石转化乙炔—气相色谱法分析含氨气体中的痕量水份

前言气体中0～30ppm痕量水份的分析一直是个困难问题。对于含氨气体,则由于氨的干扰使P_2O_5电解和色谱直接测定等方法均难以适用。这样Knight等发展的痕量水先经电石转化为乙炔,然后用气相色谱测定乙炔峰高的方法,显现出独特的优越性,即具有较高的灵敏度和一定的抗干扰能力,并可进行较远距离的多点快速分析。但此法在应用于含氨气体中痕量水的分析时,还应进一步考虑以下几个问题:(1) 大量氨的存在是否会干扰转化反应的进行;(2) 温度、流速和电石粒度等对痕量水转化反应的影     

氦离子化检测器响应特性的研究

气体中痕量杂质的分析与测定对国民经济,国防工业和科学研究等都有十分重要的意义。气相色谱法是气体中痕量杂质分析与测定的重要方法,而放射性氦离子化检测器(简写为HeD)则是测定永久性气体的高灵敏度检测器。     

活性炭吸附富集污染水中痕量硫双威及其气相色谱测定

用粒径３００－４００μｍ活性炭吸附富集环境水中痕量硫双威，气相色谱法直接测定，方法简便，快速，灵敏，准确，实用。研究了活性炭对硫双威的吸附性能及不同粒度活性炭对硫双威吸附效率的影响。进行了最佳预洗方法和最佳洗脱剂的选择。     

三通道气相色谱法测定炼厂气组成

炼厂气是炼油工艺产生的各种气体的混合物,采用四阀六柱将炼厂气分离分解为3部分,以双TCD+FID检测器3通道气相色谱法快速分析炼厂气.FID通道用于分析烃类,一个TCD通道分析永久性气体和硫化物,另一个TCD通道分析氢气,采用面积归一化法定量计算分析结果.用该法测定了3种标准气体,测定值与标准值基本一致,测定结果的相对标准偏差小于8％.该法适用于测定包括液化气、烟气、裂解气等组分相近的样品组成.     

热脱附气相色谱法测定氮中痕量二氧化硫

利用热脱附气相色谱法对工业氮气中的痕量二氧化硫进行了富集和测定。用填充TenaxTA的热脱附管吸附氮气中的二氧化硫,在300℃进行脱附后进入气相色谱仪,用火焰光度检测器进行检测,检出限为4.6 nmol/mol,线性范围为47.0～960 nmol/mol,线性相关系数r为0.9983,定量测量重复性为5.6%,常见无机气体杂质和无机硫化物均不干扰检测。     

氧化铝柱预分离-离子色谱法测定钢铁中痕量硫

采用２．２５ｍｍｏｌ／Ｌ邻苯二甲酸氢钾为流动相,以单柱阴离子色谱法测定痕量硫,硫的检出限达３μｇ／Ｌ,详细研究了氧化铝柱分离条件,实现了钢铁中痕量硫与基体快速分离并定量回收,消除了酸溶路线中大量杂质离子的干扰及重金属离子对色谱柱的危害,研究了不同基体对痕量硫测定的干扰情况及消除方法,建立了氧化铝柱预分离－ＩＣ法测定钢铁中痕量硫的新方法。     

大气中一氧化碳色谱分析所用甲烷化催化剂的研究

大气中痕量(ppm 级)的一氧化碳的测定可以采用气相色谱法,其步骤是先将一氧化碳通过催化剂与载气(氢气)作用而生成甲烷,再进入氢火焰离子化检测器进行检测。但在这个检测过程中,样品内大最空气往往反常地出现一个较大的峰,干扰一氧化碳的测定。由于这个     

顶空气相色谱法测定富氢水中的氢气

建立顶空气相色谱法测定富氢水中氢气的方法。采用顶空的方式将水中的微量氢气转移到气相中,通过分子筛色谱柱分离,用热导检测器测定。分析条件如下:分流比为5∶1,气液体积比为1.2∶1,平衡温度为40℃,平衡时间为15 min。水中氢气的质量浓度在0.080~1.603 mg/L范围内与色谱峰面积成良好线性关系,线性相关系数为0.999,方法检出限为0.005 mg/L。样品加标回收率为91.03%~94.25%,测定结果的相对标准偏差为0.61%~2.32%(n=6)。该法可用于富氢水中氢气的测定。     

气相色谱法分析天然气中氦氖氢

报道了用气相色谱法分析氦氖氢的各项条件试验,并最后确定了样品的最佳色谱条件,建立了天然气中同时测定氦氖氢的分析方法。     

醇类化合物气相色谱保留指数的分子拓扑研究

分子中原子i的特征值(ti)定义为tj＝1 ∑hi。并计算了醇类化合物的氢连接性指数，藉助多元线性回归技术分别建立了25个醇类化合物的指数与这些物质的气相色谱保留指数的定量结构／性质相关关系模型。模型具有良好的稳定性和预测能力，氢连接性指数能较好地反映化合物的结构特征。     

气相色谱法测定乙二醇生产中无机气体成分

煤制乙二醇工艺过程中,需要测定生产过程中的无机气体成分,对工艺生产作出指导.采用气相色谱法,通过一个十通阀和一个六通阀,HN填充柱与毛细管色谱柱HP-MOLESIEVE组合,经过多次实验探究优化,最终确立了高纯氩气为载气,配备恒温外置小柱箱,柱箱采用程序升温,最优的切换十通阀、六通阀时间,实现了一次性测定样品气中二氧化...     

气相色谱与液相色谱保留值的换算方法

根据色谱热力学理论,在色谱保留值公式统一形式的基础上导出了气相色谱保留系数（I）与反相液相色谱保留公式参数a,c之间的关系式,证明结构类似化合物的a,c值与保留指数呈线性关系,同时存在氢键作用能、偶极矩作用的影响,从而提出了色相色谱与反相液相色谱保留值换算的方法;该理论为氯代芳烃的文献数据所证实。     

Gas chromatography on 10 um silica particles

Summary Porous silica microparticles designed for modern liquid chromatography have proven effective in gas chromatography. Columns of 35–50 cm gave plate heights as low as 3.3 particle diameters and speeds of 2400 theoretical plates per second or 500 effective theoretical plates per second. Inlet pressures up to 70 atmospheres were required using hydrogen as carrier gas. The particles as received were too retentive for fast chromatography and gave asymmetric peaks. A coating of fluorosilicone oil overcame both problems. Other coatings were less effective. Bonded phases proved less satisfactory on both counts and also gave substantially less efficient columns and greater flow resistance. Column efficiency and flow resistance were sharply dependent on physical properties of the particles. The most efficient packing was clearly spherical particles of 5–10 μm diameter with narrow size distribution, pore diamters about 50 nm, BET surface areas of 25–50 m²/g and surfaces modified with trifluoropropyl silicone. A six-component hydrocarbon sample was separated in 33 s with a resolution of 4 for the most difficult pair and in 2.6 s with a minimal resolution. Performance was limited by end effects and by available pressure so that much better performance can be expected from longer columns and higher pressures.     

Gas chroamtographic separation of optically active compounds in glass capillaries

Summary Chiral compounds may be separated by gas chromatography by direct enantiomer separation on optically active stationary phases. More generally the separation can be achieved on conventional stationary phases after formation of diastereoisomeric derivatives. In this work we report on new results in enantiomer separation, indicating that hydrogen bond association is not the only kind of molecular interaction responsible for enantiomer separation. For the separation of a wide variety of chiral compounds with amino or hydroxy groups diastereo-isomeric derivatives may be formed by reaction with L--chlorisovaleryl chloride. The derivatives of amino acids, aliphatic and aromatic amines, amino alcohols and of some alcohols are separated in glass capillaries. Gas chromatography as a separation technique of high selectivity is specifically useful for the separation of mixtures of chemically related components with comparable molecular interactions with the molecules of the stationary phase of a gas chromatographic column. The separation of optically active compounds, particularly, requires highly efficient columns. Glass capillary chromatography is a tool that meets this standard and was applied exclusively in this work.     

Gas chromatography flow rates for determining deuterium/hydrogen ratios of natural gas by gas chromatography/high-temperature conversion/isotope ratio mass spectrometry

The effects of the gas chromatography flow rate on the determination of the deuterium/hydrogen (D/H) ratios of natural gas utilising gas chromatography/high-temperature conversion/isotope ratio mass spectrometry (GC/TC/IRMS) have been evaluated. In general, the measured deltaD values of methane, ethane and propane decrease with increase in column flow rate. When the column flow rate is 1 mL/min or higher, which is commonly used for the determination of D/H ratios of natural gas, the organic H in gas compounds may not be completely converted into hydrogen gas. Based on the results of experiments conducted on a GC column with an i.d. of 0.32 mm, a GC flow rate of 0.6 mL/min is proposed for determining the D/H ratios of natural gas by GC/TC/IRMS. Although this value may be dependent on the instrument conditions used in this work, we believe that correct deltaD values of organic compounds with a few carbon atoms are obtained only when relatively low GC flow rates are used for D/H analysis by GC/TC/IRMS. Moreover, as the presence of trace water could significantly affect the determination of D/H ratios, a newly designed inlet liner was used to remove trace water contained in some gas samples.