Chromatographic Separation Study of Gases Containing Argon and Nitrogen and Oxygen

Based on different affinities and different diffusing rates on stationary phases among components, a group of gas chromatographic methods are presented for the separation and analysis of gases containing argon and oxygen and nitrogen at ambient temperature.     

脉冲熔融-飞行时间质谱法测定金属材料中氧、氮、氢和氩

采用自主研制的脉冲熔融飞行时间质谱法可以固时测定金属中O,N,H和Ar.重点讨论质谱谱线的选择,信号获得以及数据处理和校准,并给出O,N,H和Ar 4种的检出限分别为0.021,0.060,0.002和0.002 μg/g,线性范围分别为0.070～500 μg/g,0.200～400 μg/g,0.006～40 μg...     

Adsorption of Nitrogen, Oxygen and Argon on Na-CeX Zeolites

Commercial type X zeolites (Linde 13X) are nitrogen selective. Oxygen is the less abundant component in air; hence oxygen selective sorbents are desired for air separation. Mixed Na-Ce type X zeolites containing different ratios of Ce³⁺/Na⁺ ions are prepared by partial ion exchange of commercial X zeolite. The adsorption isotherms of nitrogen, oxygen and argon are measured and the pure-component selectivity ratios are compared and analyzed against commercial zeolites (13X) for air separation. Oxygen selectivity over nitrogen (1.5) and argon (4.0) are seen for mixed Na-Ce type X zeolite (Si/Al = 1.25; Ce³⁺/Na⁺ < 4.0) from Henry's constant determined from low pressure adsorption measurements. The oxygen and nitrogen isotherms cross over for mixed Na-Ce type X zeolite (Si/Al = 1.25; Ce³⁺/Na⁺ < 4.0), and the pressure at which cross they over increases as Ce³⁺/Na⁺ approaches 1. The oxygen selectivity as claimed in the patent by N.V. Choudary, R.V. Jasra, and S.G.T. Bhat (US Patent no. 6,087,289, 2000) is seen only at very low pressures in the volumetric adsorption measurement and the hydrogen treatment of the Ce-exchanged samples have no effect on the adsorption characteristics.     

低温吸附、热解吸气相色谱法测定痕量气体硫化氢

采用GC-7890Ⅱ气相色谱仪和自行研制的控温炉,以Chromosorb G为吸附剂。液氮为冷冻剂,低温吸附大气中痕量硫化氢。在130℃下热解吸4min后,直接进入色谱分析。结果表明该方法精密度和回收率均较好。当样品体积为1L时。检出限为0．192ng/L.     

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。     

合成2,6-叔丁基对甲酚的气相色谱分析

本文介绍了对甲酚与混合C4以杂多酸为催化剂合成2.6 二叔丁基对甲酚(BHT)的气相色谱分析。此方法使用Φ3×3m不锈钢填充柱,内装涂有10%SE 30的白色硅烷化101担体,FID检测器,已知物对照法及色质联用定性。该方法测定了样品中12种化合物,以扣除溶剂的面积归一法定量。     

丙烯腈中微量杂质的毛细管色谱法分析

提出了一种分析丙烯腈中微量杂质的大孔径ＯＶ－１０１和ＯＶ－１７ＳＣＯＴ串联柱及毛细管进样系统。结果表明串联柱具有寿命长和分离效率高的特点,定量分析误差小于４％。     

Adsorption of Nitrogen,Oxygen, and Argon Vapors on Supermicroporous Oxides

The adsorption of N₂, O₂, and Ar vapors on a number of supermicroporous tin dioxide and zirconia xerogels at 77.4 K was studied. The micropore volumes calculated with the use of sorbate densities at the corresponding temperature were found to be in satisfactory agreement for all of the sorbates. At the same time, the volumes of larger pores measured using nitrogen were greater than the values found with other sorbates. The previously found behavior of oxygen and nitrogen molecules in the geometrically restricted space of supermicropores was substantiated. In particular, this behavior manifests itself in a change in the adsorption properties of a unit surface area of supermicropores as compared with the surface of mesopores. However, the effects of this kind were not found for the argon–nitrogen sorbate pair.     

The Gas Chromatographic Separation of Volatile Fluorides Using a Hydrogen Diffusion Flame as Detector

Abstract

An account is given of the preparation, separation and detection of volatile fluorides. These fluorides are formed by the reaction of chlorine trifluoride with the elements in a specially designed PTFE reaction vessel enclosed in an HF coil. A comparison is also made of a spectroscopic detector with a katharometer for the detection of the fluorides.

The separation of volatile fluorides has been reported to be partially successful on perfluorinated materials such as Kel-F oils or waxes on PTFE supports.^1–3 The present communication describes a more detailed investigation of these separations and also compares the performance of a newly developed spectroscopic detector⁴ with a conventional katharometer detector.     

气相法分析3-氯-2-羟丙基三甲基氯化铵中的微量有机杂质

 以氯仿为萃取剂 ,对 3 氯 2 羟丙基三甲基氯化铵 (CHPTMA)水溶液进行萃取 ,用气相法分析了CHPT MA溶液中的微量有机杂质环氧氯丙烷和 1 3 二氯丙醇。柱为 2m× 3mmi d 的不锈钢填充柱 ,固定相为10 %的PEG 2 0M ,载体为ChromosorbW/AW。环氧氯丙烷和 1,3 二氯丙醇的回收率分别为 97 5 %～ 10 5 0 %和93 3%～ 98 8% ,相对标准偏差分别为 11 5 %和 13 1% ,最低检测限分别为 5 0 μg/g和 10 0 μg/ g。     

Gas Chromatographic Method Optimization and Statistical Validation for the Determination of Trace Impurities in Street Doses of Heroin

This study aims to utilize the manufacturing impurities found in illicit heroin to predict whether the samples had originated from a common production batch. From highly cut heroin samples, twelve frequently extractable neutral/acidic impurities were selected for investigation. A gas chromatographic method was optimized using three locally seized samples containing the target impurities and a control sample consisting of n-alkanes. The method optimization procedures are reported in detail. The capability of the optimized method was further assessed using five simulated links prepared from unrelated heroin seizures. With the aid of principal component analysis (PCA), it was found that the statistical data pretreatment (normalization followed by standardization, N + S) showed promising results for sample classification using profiles obtained with the optimized method. Similarly, 252 street doses of highly cut samples were analyzed and the profiles were statistically decomposed by PCA after the N + S pretreatment. The statistics suggested that the locally seized samples could have originated from more than one production batch.     

Adsorption of Nitrogen,Oxygen, and Argon Vapors on Fine-Pore Oxide Materials

A comparative study of the adsorption of N₂, O₂, and Ar vapors on supermicroporous and fine-mesopore silica at 77 K is carried out. The oxygen sorption properties of these silica materials, like those of tin oxide and zirconia (earlier studied materials), are affected by supermicropores. Argon sorption is insensitive to the presence of supermicropores. Fine mesopores also have an effect on the oxygen sorption properties of silica.__________Translated from Kinetika i Kataliz, Vol. 46, No. 3, 2005, pp. 430–433.Original Russian Text Copyright © 2005 by Gavrilov.     

离子色谱法测定食品添加剂三聚磷酸盐中的杂质含量

研究了离子色谱法检测食品添加剂三聚磷酸盐中杂质含量的分析方法。用NaOH梯度淋洗,流速为1.8 mL/min,成功地同时测定了三聚磷酸盐中的Cl- NO- 3 SO2- 4 磷酸盐 焦磷酸钠 三偏磷酸钠等杂质的含量。各杂质在检测条件下有很好的线性,所测杂质的相对标准偏差范围为0.22%-8.32%。采用AS11型阴离子色谱柱,样品测定的整个过程可在15 min内完成。实验结果表明,该方法具有分析时间短 线性范围宽 灵敏准确 试剂用量少等优点。     

Chromatographic Determination of Dissociation Constants of Pramipexole and its Impurities

The main goal in this investigation was monocratic HPLC determination of dissociation constant values (pK _a) of pramipexole and its impurities, BI-II 546 CL, BI-II 751 xx and 2-aminobenzothiazole. The chromatographic method is advantageous as a small amount of substance is needed and the degree of substance purity is less important. Analysis was carried out using stationary phases stable in a wide pH range. Triethylamonium phosphoric buffer was selected as appropriate pH controlling solution because it can cover a wide pH range. Detection was done on two different wavelengths, 262 nm for pramipexole, BI-II 751 xx and 2-aminobenzothiazole and at 326 nm for BI-II 546 CL. The constants were calculated from the typical sigmoidal curves of analyte obtained as retention factor versus the pH of the mobile phase.     

离子色谱法测定茶叶中的无机阴离子

提出了离子交换色谱法分离测定茶叶中F-、Cl-、Br-、NO3-、H2PO4-和SO2-4 6种无机阴离子含量的方法.茶叶样品中6种阴离子用水在95℃超声萃取20 min后,经IonPac ASll-HC阴离子分离柱,AGll-HC阴离子保护柱,以氢氧化钾为淋洗液,浓度从15 mmol·L-1到30 mmol·L-1进行梯度淋洗.F-、Cl-和Soi2-4的峰面积与其质量浓度在0.01～150.0 mg·L-1范围内,H2PO-4、NO-3和Br-在0.05～150.0 mg·L-1范围内呈线性关系.6种离子的检出限(3S/N)均小于0.03 mg·L-1.该方法用于茶叶样品中F-、Cl-、Br-、NO-3、H2PO-4和SOi2-4的测定,加标回收率在90.9%～100.0%之间,测定值的相对标准偏差(n=5)小于3.5%.     

预浓缩系统与GC-MS联用测定环境空气中痕量挥发性有机物

目前,国内空气质量监测普遍停留在燃煤、汽车尾气引起的无机污染物(二氧化硫、二氧化氮)阶段,而对易对人体产生三致作用(致癌、致畸、致突变)的挥发性有机物(VOCs)监测由于技术原因尚未开展。现在,挥发性有机物(VOCs)对室内外空气质量及人体健康的影响已日益受到人们的关注,同时也成为国内外研究的焦点。本文采用在常温下用抽成真空的苏玛罐(内壁经过抛光处理的金属罐)或Tedlar袋进行采样,然后在实验室用预浓缩仪两级低温浓缩捕集挥发性有机物(VOCs),再进入GC-MS进行定性、定量分析,本方法灵敏度高,重复性好,适合于室内空气和环境空气中挥发性有机物(VOCs)的测定。     

羊粪挥发性成分的毛细管气相色谱分析

利用同时蒸馏萃取装置（ＳＤＥ）对羊粪中的挥发性成分进行提取，用气相色谱－质谱联用技术和气相色谱程序升温保留指数进行定性分析，质谱法共鉴定出４５种组份，占峰面积的５７．４１％，用樯样和双柱保留指数法进一步确证了其中的２８种组分、占面积的２７．８６％，比较了鸽子粪和羊粪的相同挥发成分，为了解它们的药物作用提供参考。     

脉冲熔融-飞行时间质谱法测定Nd-Fe-B材料中的氧、氮、氢

建立了脉冲熔融-飞行时间质谱法测定Nd-Fe-B材料中的氧、氮、氢的方法,在选定的实验条件下,氧、氮、氢的检出限分别为0.021,0.060,0.002μg/g;利用系列标准样品得到各元素的校准曲线,线性相关系数R2均大于0.99。将方法应用于Nd-Fe-B材料的测定,经对比实验验证,方法测定值与传统的脉冲熔融-红外/热导方法测定值相符合。     

气相色谱法分离测定空气中的有机胺类物质

本文对空气中有机胺类物质的气相色谱分离和定量测定进行了系统研究。样品经富集,分离浓缩后,可以实现对三甲胺,甲胺,乙胺的色谱分离。对排出量大、嗅觉阈值低的三甲胺(0.00021μg/ml)进行了GC定量研究,其最小检出量为0.1μg/ml,回收率达96～100％。本方法简便、快速、灵敏、准确。可用于现场样品测定。