U.S. flag

An official website of the United States government

PubAg

Main content area

You searched for: Subject "gas chromatography" Remove constraint Subject: "gas chromatography"
Start Over

Search

37,457  Search Results

« Previous | 1 - 20 of 37,457 |
Number of results to display per page

Search Results

1. Preliminary observations on the use of a novel low duty cycle flow modulator for comprehensive two-dimensional gas chromatography

Author:
Aloisi, Ivan; Giocastro, Barbara; Ferracane, Antonio; Salerno, Tania M.G.; Zoccali, Mariosimone; Tranchida, Peter Q.; Mondello, Luigi
Source:
Journal of chromatography 2021 v.1643 pp. 462076
ISSN:
0021-9673
Subject:
comprehensive two-dimensional gas chromatography; gas chromatography-mass spectrometry,   etc   ; odors;     Show all 3 Subject
Abstract:
... The present research is focused on the preliminary evaluation, in particular in relation to the advisable operational conditions, of a novel low duty cycle flow modulator. In such a respect, a fast comprehensive two-dimensional gas chromatography-mass spectrometry method is herein proposed. Applications on a C₇-C₃₀ series of alkanes, 64 fragrance allergens (plus 2 internal standards), and 5 perfum ...
DOI:
10.1016/j.chroma.2021.462076

2. The retention index approach in liquid chromatography: An historical review and recent advances

Author:
Rigano, Francesca; Arigò, Adriana; Oteri, Marianna; La Tella, Roberta; Dugo, Paola; Mondello, Luigi
Source:
Journal of chromatography 2021 v.1640 pp. 461963
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; databases; liquid chromatography; spectrometers;     Show all 4 Subjects
Abstract:
... Historically, retention parameters were reliably used as identification criterion in chromatographic analytical systems. However, pure analytical standards are necessary to determine the retention behaviour of a given compound. In recent decades, mass spectrometer (MS) became the detector of choice to obtain structural information on unknown peaks, thanks to the elucidation of fragments, often ari ...
DOI:
10.1016/j.chroma.2021.461963

3. Mapping of fatty acids composition in shelled almonds analysed in bulk using a Hyperspectral Imaging system

Author:
Torres, Irina; Pérez-Marín, Dolores; Vega-Castellote, Miguel; Sánchez, María-Teresa
Source:
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2021 v.138 pp. 110678
ISSN:
0023-6438
Subject:
gas chromatography,   etc   ; fatty acid composition; prediction; reflectance;     Show all 4 Subjects
Abstract:
... The determination of the fatty acid profile in food products is an important issue, as it serves as a guide to consumers who wish to follow healthy diets. Hyperspectral Imaging (HSI), permits rapid, non-destructive quality evaluation in foods by integrating the spatial dimension of the composition distribution. The aim of this research was to measure the fatty acid profile of almonds using HSI in ...
DOI:
10.1016/j.lwt.2020.110678

4. The history of electron ionization in LC-MS, from the early days to modern technologies: A review

Author:
Famiglini, Giorgio; Palma, Pierangela; Termopoli, Veronica; Cappiello, Achille
Source:
Analytica chimica acta 2021 pp. 338350
ISSN:
0003-2670
Subject:
gas chromatography-mass spectrometry,   etc   ; ionization; liquid chromatography;     Show all 3 Subjects
Abstract:
... This review article traces the history of the use of liquid chromatography coupled with mass spectrometry (LC-MS) using electron ionization (EI) from the first attempts up to the present day. At the time of the first efforts to couple LC to MS, 70 eV EI was the most common ionization technique, typically used in gas chromatography-mass spectrometry (GC-MS) and providing highly reproducible mass sp ...
DOI:
10.1016/j.aca.2021.338350

5. Development of retention time indices for comprehensive multidimensional gas chromatography and application to ignitable liquid residue mapping in wildfire investigations

Author:
Boegelsack, Nadin; Sandau, Court; McMartin, Dena W.; Withey, Jonathan M.; O'Sullivan, Gwen
Source:
Journal of chromatography 2021 v.1635 pp. 461717
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; ; chemometrics; liquids; variance; wildfires;     Show all 6 Subjects
Abstract:
... In this study, we introduce a simple three-step workflow for a universally applicable RI system, to be used in GC×GC analysis of ignitable liquid residue (ILR) for arson investigations. The proposed RI system applies a combination of two well-established GC RI systems: non-isothermal Kovats (K) index in the first dimension and Lee (L) index in the second dimension. The proposed KLI RI system showe ...
DOI:
10.1016/j.chroma.2020.461717

6. Techniques and application in comprehensive multidimensional gas chromatography – mass spectrometry

Author:
Marriott, Philip J.; Chin, Sung-Tong; Nolvachai, Yada
Source:
Journal of chromatography 2021 v.1636 pp. 461788
ISSN:
0021-9673
Subject:
comprehensive two-dimensional gas chromatography; gas chromatography,   etc   ; mass spectrometry; petroleum; probability;     Show all 5 Subjects
Abstract:
... In contrast to the well-known comprehensive two-dimensional gas chromatography (GC×GC) method, it is possible to define comprehensive multidimensional gas chromatography. ‘Comprehensiveness’ relates to analysis of the whole sample. Two-dimensional and multidimensional here refer to the use of at least two separation stages for analysis, however comprehensive 2DGC now appears to be reserved for the ...
DOI:
10.1016/j.chroma.2020.461788

7. Ionic Liquid Stationary Phase for Improving Comprehensive Two-dimensional Gas Chromatographic Separation of Polychlorinated Naphthalenes

Author:
Ayala-Cabrera, J.F.; Lipok, C.; Li, J.; Moyano, E.; Schmitz, O.J.; Santos, F.J.
Source:
Journal of chromatography 2021 v.1635 pp. 461732
ISSN:
0021-9673
Subject:
comprehensive two-dimensional gas chromatography; gas chromatography,   etc   ; ionic liquids; mass spectrometry; ovens; temperature; toxicity;     Show all 7 Subjects
Abstract:
... The performance of comprehensive two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) using a column combination of a non-polar stationary phase (DB-5MS) and an ionic liquid stationary phase (SLB-IL60) in the first- and the second dimension has been evaluated for the suitable separation of polychlorinated naphthalenes (PCNs). The optimization of the GC×GC-MS method was carrie ...
DOI:
10.1016/j.chroma.2020.461732

8. Predicting Kováts Retention Indices Using Graph Neural Networks

Author:
Qu, Chen; Schneider, Barry I.; Kearsley, Anthony J.; Keyrouz, Walid; Allison, Thomas C.
Source:
Journal of chromatography 2021 v.1646 pp. 462100
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; data collection; databases; neural networks; prediction;     Show all 5 Subjects
Abstract:
... The Kováts retention index is a dimensionless quantity that characterizes the rate at which a compound is processed through a gas chromatography column. This quantity is independent of many experimental variables and, as such, is considered a near-universal descriptor of retention time on a chromatography column. The Kováts retention indices of a large number of molecules have been determined expe ...
DOI:
10.1016/j.chroma.2021.462100

9. Cryogenic trapping as a versatile approach for sample handling, enrichment and multidimensional analysis in gas chromatography

Author:
Novaes, Fábio Junior Moreira; Marriott, Philip John
Source:
Journal of chromatography 2021 v.1644 pp. 462135
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; chemical species; cold; sorbents; sorption; temperature;     Show all 6 Subjects
Abstract:
... Cryogenic methods – those that employ cryogenic fluids/gases but also other approaches to generate reduced temperature – are versatile, functional and relatively easily implemented as part of a total gas chromatographic method. The general utility of a cold region is almost invariably as a trapping or focussing step, to collect analyte into a sharp zone. The success in effectively trapping analyte ...
DOI:
10.1016/j.chroma.2021.462135

10. Modulating solvation interactions of deep eutectic solvents formed by ammonium salts and carboxylic acids through varying the molar ratio of hydrogen bond donor and acceptor

Author:
Abbasi, Nabeel Mujtaba; Farooq, Muhammad Qamar; Anderson, Jared L.
Source:
Journal of chromatography 2021 v.1643 pp. 462011
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; acidity; ammonium; dyes; hydrogen bonding; solvation; stoichiometry;     Show all 7 Subjects
Abstract:
... Deep eutectic solvents (DESs) have gained increasing popularity in separation science due to the fact that their physico-chemical properties can be easily fine-tuned by varying the type or ratio of hydrogen bond acceptor (HBA) and hydrogen bond donor (HBD). While it is well-known that the molar ratio of HBA/HBD affects the melting point of a eutectic mixture, much less is understood regarding its ...
DOI:
10.1016/j.chroma.2021.462011

11. Smart filters for the analysis of microplastic in beverages filled in plastic bottles

Author:
Braun, Ulrike; Altmann, Korinna; Herper, Dominik; Knefel, Markus; Bednarz, Marius; Bannick, Claus G.
Source:
Food additives & contaminants 2021 v.38 no.4 pp. 691-700
ISSN:
1944-0057
Subject:
gas chromatography-mass spectrometry,   etc   ; desorption; filtration; infrastructure; microplastics; quantitative analysis;     Show all 6 Subjects
Abstract:
... The occurrence of microplastic (MP) in food products, such as beverages in plastic bottles, is of high public concern. Existing analytical methods focus on the determination of particle numbers, requiring elaborate sampling tools, laboratory infrastructure and generally time-consuming imaging detection methods. A comprehensive routine analysis of MP in food products is still not possible. In the p ...
DOI:
10.1080/19440049.2021.1889042

12. Determination of activity of denitrifying enzyme in soil samples by a headspace gas chromatographic technique

Author:
Zhang, Xu-Bo; Hu, Zhan-Bo; Chai, Xin-Sheng; Zhong, Guang-Zhi; Ouyang, Xiao; Li, Pei-Yi
Source:
Journal of chromatography 2021 v.1638 pp. 461882
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; denitrification; enzyme activity; enzymes; headspace analysis; soil;     Show all 6 Subjects
Abstract:
... This paper reported a headspace gas chromatography (HS-GC) for the determination of denitrifying enzyme activity in soil samples. It was based on measuring the NO₂ signal in a set of closed/air-free vials containing soil samples that incubated at the designated conditions. The results showed that the method has a good measurement precision (RSD < 5.0%) and reasonable accuracy for determining the d ...
DOI:
10.1016/j.chroma.2021.461882

13. Determination of physicochemical properties of ionic liquids by gas chromatography

Author:
Poole, Colin F.; Atapattu, Sanka N.
Source:
Journal of chromatography 2021 pp. 461964
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; ambient temperature; models; solubility; solvation; thermal stability;     Show all 6 Subjects
Abstract:
... Over the years room temperature ionic liquids have gained attention as solvents with favorable environmental and technical features. Both chromatographic and conventional methods afford suitable tools for the study of their physicochemical properties. Use of gas chromatography compared to conventional methods for the measurement of physicochemical properties of ionic liquids have several advantage ...
DOI:
10.1016/j.chroma.2021.461964

14. Sensory-directed characterisation of distinctive aromas of Sauternes and Viognier wines through semi-preparative liquid chromatography and gas chromatography approaches

Author:
Siebert, Tracey E.; Stamatopoulos, Panagiotis; Francis, I. Leigh; Darriet, Philippe
Source:
Journal of chromatography 2021 v.1637 pp. 461803
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; benzaldehyde; dessert wines; ethanol; geraniol; linalool; odors; spectroscopy;     Show all 8 Subjects
Abstract:
... Gas chromatography-olfactometry-mass spectrometry (GC-O-MS) has been very useful in identifying aroma compounds from within the complex matrix of wine. Supplementary separation can be required to overcome co-elution of volatiles or other sensory-directed chromatographic strategies are needed, including multidimensional chromatography and preparative fraction collection coupled to GC. Studies inves ...
DOI:
10.1016/j.chroma.2020.461803

15. A chiral metal-organic cage used as the stationary phase for gas chromatography separations

Author:
Tang, Bo; Zhang, Xin; Geng, Lina; Sun, Liquan; Luo, Aiqin
Source:
Journal of chromatography 2021 v.1636 pp. 461792
ISSN:
0021-9673
Subject:
gas chromatography,   etc   ; alkanes; chemical species; phenylalanine; standard deviation;     Show all 5 Subjects
Abstract:
... Chiral metal-organic cages (MOCs) are a new type of porous materials with unique molecular recognition ability, which have received research attention as a chiral stationary phase (CSP) for gas chromatography (GC). Herein, we report the detailed investigation of a chiral MOC ([Cu₁₂(LPA)₁₂(H₂O)₁₂], PA = L-phenylalanine, MOC-PA) as a novel stationary phase for GC separations. The MOC-PA capillary co ...
DOI:
10.1016/j.chroma.2020.461792

16. Gas products generation mechanism during co-pyrolysis of styrene-butadiene rubber and natural rubber

Author:
Yang, Qirong; Yu, Shuangpeng; Zhong, Haowen; Liu, Ting; Yao, Erren; Zhang, Yuan; Zou, Hansen; Du, Wei
Source:
Journal of hazardous materials 2021 v.401 pp. 123302
ISSN:
0304-3894
Subject:
gas chromatography,   etc   ; energy; molecular dynamics; pyrolysis; rubber; styrene; temperature;     Show all 7 Subjects
Abstract:
... In this study, reaction molecular dynamics were combined with experiments to gain in-depth understanding of the gaseous pyrolysis products generation mechanism and optimal paths during natural rubber (NR), styrene-butadiene rubber (SBR) and mixed rubbers (NR-SBR) for effective recovery of waste rubber. The results show that the pyrolysis temperature of NR increases gradually with SBR addition. The ...
DOI:
10.1016/j.jhazmat.2020.123302

17. Characterization of lactones in Wagyu (Japanese beef) and imported beef by combining solvent extraction and gas chromatography–mass spectrometry

Author:
Yoshinaga, Kazuaki; Tago, Arisa; Yoshinaga-Kiriake, Aya; Gotoh, Naohiro
Source:
Lebensmittel-Wissenschaft + [i.e. und] Technologie 2021 v.135 pp. 110015
ISSN:
0023-6438
Subject:
gas chromatography-mass spectrometry,   etc   ; Japan; Wagyu; beef; solvents;     Show all 5 Subjects
Abstract:
... The lactone content of Wagyu beef and imported beef in Japan was estimated using a combination of solvent extraction and gas chromatography–tandem quadrupole mass spectrometry. This method revealed that the total lactone content was higher in Wagyu than in the imported beef. The most abundant lactone in the Wagyu and imported beef was δ-hexadecalactone, followed by δ-tetradecalactone, δ-dodecalact ...
DOI:
10.1016/j.lwt.2020.110015

18. Characterization of the key aroma compounds in Laoshan green teas by application of odour activity value (OAV), gas chromatography-mass spectrometry-olfactometry (GC-MS-O) and comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-qMS)

Author:
Zhu, JianCai; Niu, Yunwei; Xiao, ZuoBing
Source:
Food chemistry 2021 v.339 pp. 128136
ISSN:
0308-8146
Subject:
comprehensive two-dimensional gas chromatography; gas chromatography-mass spectrometry,   etc   ; dimethyl sulfide; food chemistry; odors; photometry; skatole; vanillin;     Show all 8 Subjects
Abstract:
... To investigate the key aroma compounds in Laoshan green teas (Huangshan (S1), Changling (S2), and Fangling (S3)), gas chromatography-mass spectrometry-olfactometry (GC-MS-O), a flame photometric detector (FPD), odor activity value (OAV), and comprehensive two-dimensional gas chromatography mass spectrometry (GC × GC-qMS) were employed. A total of 50 aroma compounds were perceived and 24 compounds ...
DOI:
10.1016/j.foodchem.2020.128136

19. GC × VUV Study of Diesel: A Two-Dimensional Separation Approach

Author:
Wang, Frank Cheng-Yu
Source:
Energy & fuels 2020 v.34 no.2 pp. 1432-1437
ISSN:
1520-5029
Subject:
comprehensive two-dimensional gas chromatography; gas chromatography,   etc   ; petroleum; spectroscopy; wavelengths;     Show all 5 Subjects
Abstract:
... The characterization of complex hydrocarbon mixtures remains a challenging task. Advances in analytical characterization have been made in several fronts. One such advance is in gas chromatography–vacuum ultraviolet spectrometry (GC-VUV), which allows for sensitive, universal detection that is particularly well suited for characterizing petroleum and petroleum products. As complete VUV (125–430 nm ...
DOI:
10.1021/acs.energyfuels.9b03383

20. The effect of column and temperature variation on the determination of the dead time in gas chromatographic systems using indirect methods

Author:
Idroes, Rinaldi; Muslem,; Mahmudi,; Saiful,; Idroes, Ghazi Mauer; Suhendra, Rivansyah; Irvanizam,
Source:
Heliyon 2020 v.6 no.2 pp. e03302
ISSN:
2405-8440
Subject:
gas chromatography,   etc   ; alkanes; statistics; temperature;     Show all 4 Subjects
Abstract:
... The precise determination of the dead time is essential in a chromatography system as it is a primary parameter for the determination of other secondary parameters such as the adjusted retention time, relative retention time, retention factor and retention index. Several of the indirect methods used for the determination of the dead time in this study were iteration, nonlinear, spreadsheet and sta ...
DOI:
10.1016/j.heliyon.2020.e03302