A Method for Measuring Total Protium and Total Deuterium in a Gas Mixture Containing Protium, Deuterium, and Protium-Deuterium Mixture Using Gas Chromatography

2021 ◽  
pp. 243-254
Author(s):  
Henry T. Sessions ◽  
Simona E. Hunyadi Murph
Keyword(s):  
Gas Chromatography ◽  
Gas Mixture

DlCO measurements with gas chromatography

1962 ◽  
Vol 17 (6) ◽  
pp. 856-860 ◽  
Author(s):  
Josef R. Smith ◽  
Lyle H. Hamilton
Keyword(s):  
Gas Chromatography ◽  
Normal Subjects ◽  
Inert Gas ◽  
Breath Holding ◽  
Gas Mixture ◽  
Diffusing Capacity ◽  
Gas Chromatograph ◽  
Excellent Correlation ◽  
Pulmonary Diffusing Capacity ◽  
The Mean

A gas chromatograph has been used to analyze gases for the measurement of pulmonary diffusing capacity using the breath-holding technique. The gas mixture used for the measurement consisted of carbon monoxide in air with neon as the insoluble inert gas. The calculated DlCO was unaffected when sulphur hexafloride (SF6) or He was substituted for Ne in the mixture, but since CO and Ne could be most simply and rapidly analyzed, this combination was preferred for the gas mixture used to measure DlCO. The mean DlCO for ten normal subjects was 25.8 ± 4.2 ml/min mm Hg. These results were comparable to values reported in the literature when established methods of analysis were used. An excellent correlation was found between calculated DlCO and the clinical condition of patients with impaired pulmonary diffusing capacity. Submitted on February 14, 1962

scholarly journals Relationship between Stationary and Mobile Phase Composition and its Influence on the Retention Time of Some Analytes in Gas Chromatography

2000 ◽  
Vol 18 (4) ◽  
pp. 323-331
Author(s):  
R. Nasuto
Keyword(s):  
Gas Chromatography ◽  
Mobile Phase ◽  
Hydrogen Gas ◽  
Gas Mixture ◽  
Frontal Analysis ◽  
Mobile Phase Composition ◽  
Column Packing ◽  
Chromatographic Process ◽  
Mobile Phase Modifier ◽  
Methanol Vapour

A binary methanol vapour/hydrogen gas mixture has been used as the mobile phase in gas chromatography. Through the use of modified frontal analysis (undertaken just before measurements of the retention of the tested analytes), it has been possible to determine the adsorption isotherm of the mobile phase modifier (methanol) under typical conditions for a chromatographic process. It was found that adsorption of the mobile phase modifier on the column packing surface caused a decrease in the retention times of all the analytes tested. Furthermore, as a result of such adsorption, an increase in the degree of hydrophobization of the column packing surface also occurred, leading to a decrease of the selectivity of the packing.

A 3D-printed metal column for micro gas chromatography

Lab on a Chip ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 3435-3444
Author(s):  
Sooyeol Phyo ◽  
Sung Choi ◽  
Jaeheok Jang ◽  
Sun Choi ◽  
Jiwon Lee
Keyword(s):  
Gas Chromatography ◽  
Stationary Phase ◽  
Gas Mixture ◽  
Mixture Separation ◽  
Phase Coating ◽  
3D Printed ◽  
Pre Treatment

A square spiral 1 m-long column for gas mixture separation was 3D-printed out with the dimensions of 3.4 × 3.3 × 0.2, followed by pre-treatment and stationary phase coating.

Quantitative determination of gas mixture composition by gas chromatography—New approach

2001 ◽  
Vol 54 (7-8) ◽  
pp. 541-543
Author(s):  
L. Odochian ◽  
M. Şabliovschi ◽  
M. Dumitraş
Keyword(s):  
Gas Chromatography ◽  
Quantitative Determination ◽  
Mixture Composition ◽  
Gas Mixture ◽  
New Approach

scholarly journals Development of Open-Tubular-Type Micro Gas Chromatography Column with Bump Structures

Sensors ◽  
2019 ◽  
Vol 19 (17) ◽  
pp. 3706
Author(s):  
Lee ◽  
Lim
Keyword(s):  
Gas Chromatography ◽  
Stationary Phase ◽  
Separation Efficiency ◽  
Theoretical Plate ◽  
Microfluidic Channel ◽  
Gas Analysis ◽  
Gas Mixture ◽  
Micro Electro Mechanical Systems ◽  
Medical Diagnoses ◽  
Tubular Type

Gas chromatography (GC) is the chemical analysis technique most widely used to separate and identify gas components, and it has been extensively applied in various gas analysis fields such as non-invasive medical diagnoses, indoor air quality monitoring, and outdoor environmental monitoring. Micro-electro-mechanical systems (MEMS)-based GC columns are essential for miniaturizing an integrated gas analysis system (Micro GC system). This study reports an open-tubular-type micro GC (μ-GC) column with internal bump structures (bump structure μ-GC column) that substantially increase the interaction between the gas mixture and a stationary phase. The developed bump structure μ-GC column, which was fabricated on a 2 cm × 2 cm μ-GC chip and coated with a non-polar stationary phase, is 1.5 m-long, 150 μm-wide, and 400 μm-deep. It has an internal microfluidic channel in which the bumps, which are 150 μm diameter half-circles, are alternatingly disposed to face each other on the surface of the microchannel. The fabricated bump structure μ-GC column yielded a height-equivalent-to-a-theoretical-plate (HETP) of 0.009 cm (11,110 plates/m) at an optimal carrier gas velocity of 17 cm/s. The mechanically robust bump structure μ-GC column proposed in this study achieved higher separation efficiency than a commercially available GC column and a typical μ-GC column with internal post structures classified as a semi-packed-type column. The experimental results demonstrate that the developed bump structure μ-GC column can separate a gas mixture completely, with excellent separation resolution for formaldehyde, benzene, toluene, ethylbenzene, and xylene mixture, under programmed operating temperatures.

Fast gas chromatography–mass spectrometry method for the detection of gas phase composition of polyurethane foam and its role in foam thermal conductivity

2020 ◽  
Vol 56 (5) ◽  
pp. 531-545
Author(s):  
Anastasiia Galakhova ◽  
Gisbert Riess
Keyword(s):  
Mass Spectrometry ◽  
Thermal Conductivity ◽  
Gas Chromatography ◽  
Polyurethane Foam ◽  
Polyurethane Foams ◽  
Gas Chromatography Mass Spectrometry ◽  
Gas Mixture ◽  
Spectrometry Method ◽  
Mass Spectrometry Method ◽  
Chromatography Mass Spectrometry

This paper presents an enhanced gas chromatography–mass spectrometry method for the separation of cell gases in polyurethane foam. The novel method was then tested on several polyurethane foams produced at different mixing times, showing successful results. The measurement of gas content in polyurethane foams has been rarely considered in published literature. This parameter, indeed, plays a critical role in the deterioration of polyurethane foam thermal conductivity. This is because of the diffusion of gases which is the main mechanism of foam aging. Hence, an improved gas chromatography–mass spectrometry method was developed to offer simultaneous separation of several types of gas in only one column, using gas chromatography as its main concept. The composition of a sample gas consisting of N2, O2, CO2, and C5H10 was accurately calculated by measuring the ratio of each peak area on the chromatograms, with argon being used for sampling. This fast and simple method was found to be useful, on one hand for the accurate determination of C5H10 and CO2 cell gases used as blowing agents, and on the other hand for N2 and O2 air gases that diffuse rapidly from the surrounding environment into foam cells. The effect of mixing time on foam kinetics, cellular structure, foam thermal conductivity, and the overall thermal conductivity of cell gas mixture was also investigated. By complex analysis of foam density, the presence of open cells, cell size, and thermal conductivity of cell gas mixture, the lowest measured value of foam thermal conductivity was explained. The major goal of these experiments was to show the importance of foam cell gas analysis, together with foam structure, which is uniquely done to contribute to the understanding of polyurethane foam thermal conductivity. The thermal conductivity of cell gas mixture is considered as an example of the potential applications of this novel gas chromatography–mass spectrometry method.

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