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Micro gas chromatograph

Juan Zheng, Cuiming Lu, Junlong Huang, Luyi Chen, Chuyi Ni, Xintong Xie, Fang Zhu, Dingcai Wu, Gangfeng Ouyang
Novel powdery polymer aerogel (PPA) prepared via the (micro)emulsion polymerization and the following hyper crosslinking reaction was fabricated as stationary phase of capillary column for the first time. Due to its powdery morphology, unique 3D nano-network structure, high surface area and good thermostability, the PPA-coated capillary column demonstrated high-resolution chromatographic separation towards nonpolar and weakly polar organic compounds, including benzene series, n-alkanes, ketone mixtures and trichlorobenzenes...
August 15, 2018: Talanta
Allison A Baczynski, Pratigya J Polissar, Dieter Juchelka, Johannes Schwieters, Andreas Hilkert, Roger E Summons, Katherine H Freeman
RATIONALE: We report modifications to compound-specific isotope analyses (CSIA) to enable high-precision isotopic analyses of picomoles of carbon for intact organic molecules. This sample size is two orders of magnitude below the amounts required for commercial systems. The greatly enhanced sensitivity of this system expands molecular isotope studies and applications previously prohibited by low concentrations and small samples. METHODS: We utilize the resolving power and low volumetric flow rates of narrow-bore capillary gas chromatography to improve sample transfer efficiency while maintaining narrow peak widths...
May 15, 2018: Rapid Communications in Mass Spectrometry: RCM
Jhy-Charm Soo, Eun Gyung Lee, Ryan F LeBouf, Michael L Kashon, William Chisholm, Martin Harper
The objective of this present study was to evaluate the performance of a portable gas chromatograph-photoionization detector (GC-PID), under various test conditions to determine if it could be used in occupational settings. A mixture of 7 volatile organic compounds (VOCs)-acetone, ethylbenzene, methyl isobutyl ketone, toluene, m-xylene, p-xylene, and o-xylene-was selected because its components are commonly present in paint manufacturing industries. A full-factorial combination of 4 concentration levels (exposure scenarios) of VOC mixtures, 3 different temperatures (25°C, 30°C, and 35°C), and 3 relative humidities (RHs; 25%, 50%, and 75%) was conducted in a full-size controlled environmental chamber...
April 2018: Journal of Occupational and Environmental Hygiene
M Ros, J Escobar-Arnanz, M L Sanz, L Ramos
The feasibility of six ionic liquid- (IL-) based stationary phases for the analysis of environmentally important polychlorinated biphenyls (PCBs) by gas chromatography combined with either electron capture micro-detector (GC-micro-ECD) or quadrupole mass spectrometry (GC-MS, for confirmation) have been evaluated. These IL-based columns showed a separation mechanism different from that observed for other commercial phases, such a low bleed high temperature 8% phenyl (equiv.) polycarborane-siloxane suggested shape-selective phase for non-ortho and mono-ortho-CBs, HT-8, or a polar poly(ethylene glycol), resulting in a different elution order of the 69 investigated PCBs...
December 12, 2017: Journal of Chromatography. A
Ruth Suárez, Sabrina Clavijo, Alba González, Víctor Cerdà
An on-line, fast, simple, selective, and sensitive method has been developed for the determination of three herbicides belonging to the following families: triazines (atrazine), chloroacetamide (alachlor), and phenoxy (2,4-dichlorophenoxyacetic acid) in water samples. The method involves an in-syringe magnetic stirring-assisted dispersive liquid-liquid microextraction along with simultaneous silylation prior to their determination by gas chromatography with mass spectrometry. Extraction, derivatization, and preconcentration have been simultaneously performed using acetone as dispersive solvent, N-methyl-N-tert-butyldimethylsilyltrifluoroacetamide as derivatization agent and trichloroethylene as extraction solvent...
March 2018: Journal of Separation Science
Hiroyuki Asakura, Saburo Hosokawa, Toshiaki Ina, Kazuo Kato, Kiyofumi Nitta, Kei Uera, Tomoya Uruga, Hiroki Miura, Tetsuya Shishido, Junya Ohyama, Atsushi Satsuma, Katsutoshi Sato, Akira Yamamoto, Satoshi Hinokuma, Hiroshi Yoshida, Masato Machida, Seiji Yamazoe, Tatsuya Tsukuda, Kentaro Teramura, Tsunehiro Tanaka
The dynamic behavior of Rh species in 1 wt% Rh/Al2 O3 catalyst during the three-way catalytic reaction was examined using a micro gas chromatograph, a NOx meter, a quadrupole mass spectrometer, and time-resolved quick X-ray absorption spectroscopy (XAS) measurements at a public beamline for XAS, BL01B1 at SPring-8, operando. The combined data suggest different surface rearrangement behavior, random reduction processes, and autocatalytic oxidation processes of Rh species when the gas is switched from a reductive to an oxidative atmosphere and vice versa...
January 10, 2018: Journal of the American Chemical Society
Yong Zhou, Enguo Chen, Xiaohong Wu, Yanjie Hu, Huiqing Ge, Peifeng Xu, Yingchang Zou, Joy Jin, Ping Wang, Kejing Ying
OBJECTIVE: This study works to develop novel models that may be adopted for earlier non-invasive breathomics tests to determine pneumonia pathogens. METHODS: Two types of pneumonia models were created, both in vitro and in vivo . Paraneoplasm lung tissue and specific pathogen-free (SPF) rabbits were adopted and separately challenged with sterile saline solution control or three pathogens: Escherichia coli , Staphylococcus aureus , and Pseudomonas aeruginosa . After inoculation, headspace air or exhaled air were absorbed by solid phase micro-extraction (SPME) fibers and subsequently analyzed with gas chromatograph Mass Spectrometer (GCMS)...
2017: American Journal of Translational Research
Huan Yuan, Xiaosong Du, Huiling Tai, Ming Xu
We report the fabrication and performance of a silicon-on-glass micro gas chromatography eight-capillary column based on microelectromechanical systems technology that is 50 cm long, 30 μm wide, and 300 μm deep. According to the theory of a gas chromatography column, an even gas flow among different capillaries play a vital role in the peak broadening. Thus, a flow splitter structure is designed by the finite element method through the comparison of the velocity distributions of the eight-capillary columns with and without splitter as well as an open tubular column...
February 2018: Journal of Separation Science
Bartłomiej Witkowski, Anna Duchnowicz, Monika Ganeczko, Agnieszka Laudy, Tomasz Gierczak, Magdalena Biesaga
Simplified method for simultaneous identification of proteins, drying oils, waxes and resins in the works-of-art samples was developed. Liquid chromatography with mass spectrometry and gas chromatography with mass spectrometry were used to identify natural materials most frequently encountered in historical paintings. Protein binders were extracted with ammonia and purified using miniaturized solid-phase microextraction (Omix tips) to efficiently suppress matrix interferences. Zwitterionic stationary phase was used for separation of sixteen underivatized amino acids analysis with hydrophilic interaction liquid chromatography that were subsequently quantified with liquid chromatography with mass spectrometry...
November 18, 2017: Journal of Separation Science
Mitchell M McCartney, Yuriy Zrodnikov, Alexander G Fung, Michael K LeVasseur, Josephine M Pedersen, Konstantin O Zamuruyev, Alexander A Aksenov, Nicholas J Kenyon, Cristina E Davis
We have developed a simple-to-manufacture microfabricated gas preconcentrator for MEMS-based chemical sensing applications. Cavities and microfluidic channels were created using a wet etch process with hydrofluoric acid, portions of which can be performed outside of a cleanroom, instead of the more common deep reactive ion etch process. The integrated heater and resistance temperature detectors (RTDs) were created with a photolithography-free technique enabled by laser etching. With only 28 V DC (0.1 A), a maximum heating rate of 17...
August 25, 2017: ACS Sensors
Puneet Kumar Verma, Dinesh Sah, K Maharaj Kumari, Anita Lakhani
Aerosol samples in the dual-phase (gaseous and particulate) were collected simultaneously for the first time in Agra at a rural and a traffic dominated site during post-monsoon and winter seasons to investigate the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). The samples were collected using a high volume sampler on quartz micro-fiber filter papers and polyurethane foam plugs for particulate and gas phases respectively. The samples were extracted in a mixture of DCM and n-hexane. 16 priority PAHs and two nitro-PAHs were analyzed using gas chromatograph-mass spectrometry...
August 16, 2017: Environmental Science. Processes & Impacts
Amila M Devasurendra, Cheng Zhang, Joshua A Young, L M Viranga Tillekeratne, Jared L Anderson, Jon R Kirchhoff
Pyrrole was covalently bonded to 1-methyl and 1-benzylimidazolium ionic liquids (ILs) via an N-substituted alkyl linkage to prepare electropolymerizable IL monomers with excellent thermal stability. The methylimidazolium IL, [pyrrole-C6MIm](+), was then electropolymerized on macro- and microelectrode materials to form conductive polymeric IL (CPIL)-modified surfaces. Electrochemical characterization of a 1.6 mm diameter Pt disk electrode modified with poly[pyrrole-C6MIm](+) demonstrated a selective uptake for an anionic redox probe while rejecting a cationic redox probe...
July 17, 2017: ACS Applied Materials & Interfaces
Bishnu P Regmi, Ryan Chan, Masoud Agah
Gas chromatography columns fabricated using microelectromechanical system (MEMS) technology provide a number of clear advantages. However, successful deposition of stationary phases having a wide application range remains an important technical challenge. In this paper, we report, for the first time, on the deposition of room temperature ionic liquids (RTILs)-a versatile class of stationary phases-inside the channels of semi-packed columns (SPCs) for high-performance gas chromatographic separation of complex chemical mixtures...
August 11, 2017: Journal of Chromatography. A
Balázs Klencsár, Lieve Balcaen, Filip Cuyckens, Frédéric Lynen, Frank Vanhaecke
A novel quantification approach, compensating for the effect of gradient elution on the instrumental response during reversed phase high-performance liquid chromatography - inductively coupled plasma - tandem mass spectrometry analysis, has been developed and validated. As a proof of concept, diclofenac and its related compounds, including its major metabolite i.e. 4'-hydroxy-diclofenac, have been quantitatively determined in human plasma matrix. An inductively coupled plasma - tandem mass spectrometer has been applied for the interference-free determination of Cl as35 ClH2 + using H2 as a reaction gas in the collision/reaction cell...
June 29, 2017: Analytica Chimica Acta
Michelle R Peace, Rose I Krakowiak, Carl E Wolf, Alphonse Poklis, Justin L Poklis
MDMB-FUBINACA (aka MDMB(N)-Bz-F), chemical name Methyl (S)-2-(1-(4-fluorobenzyl)-1H-indazole-3-carboxamido)-3,3-dimethylbutanoate, a designer drug or a new psychoactive substance (NPS), was identified in three commercially available e-liquids formulated for electronic cigarette use. The e-liquids were evaluated using direct analysis in real time ion source attached to a time of flight mass spectrometer (DART-MS) and gas chromatograph mass spectrometer (GC-MS) to identify active ingredients/drugs, flavorants, and other possible constituents...
February 2017: Forensic Science International
Ryan J Milcarek, Michael J Garrett, Amrish Baskaran, Jeongmin Ahn
Combustion based power generation has been accomplished for many years through a number of heat engine systems. Recently, a move towards small scale power generation and micro combustion as well as development in fuel cell research has created new means of power generation that combine solid oxide fuel cells with open flames and combustion exhaust. Instead of relying upon the heat of combustion, these solid oxide fuel cell systems rely on reforming of the fuel via combustion to generate syngas for electrochemical power generation...
October 2, 2016: Journal of Visualized Experiments: JoVE
Liu Yang, Jie Zhang, Faqiong Zhao, Baizhao Zeng
In this work, a novel poly(3,4-ethylenedioxythiophene)@Au nanoparticles (PEDOT@AuNPs) hybrid coating was prepared and characterized. Firstly, the monomer 3,4-ethylenedioxythiophene was self-assembled on AuNPs, and then electropolymerization was performed on a stainless steel wire by cyclic voltammetry. The obtained PEDOT@AuNPs coating was rough and showed cauliflower-like micro-structure with thickness of ∼40μm. It displayed high thermal stability (up to 330°C) and mechanical stability and could be used for at least 160 times of solid phase microextraction (SPME) without decrease of extraction performance...
November 4, 2016: Journal of Chromatography. A
Rosa Ana Pérez, Beatriz Albero, José Luis Tadeo, Consuelo Sánchez-Brunete
A rapid extraction procedure is presented for the determination of five endocrine-disrupting compounds, estrone, ethinylestradiol, bisphenol A, triclosan, and 2-ethylhexylsalicylate, in water samples. The analysis involves a two-step extraction procedure that combines dispersive liquid-liquid microextraction (DLLME) with dispersive micro-solid phase extraction (D-μ-SPE), using magnetic nanoparticles, followed by in situ derivatization in the injection port of a gas chromatograph coupled to triple quadrupole mass spectrometry...
November 2016: Analytical and Bioanalytical Chemistry
Beate Gruber, Thomas Groeger, Dale Harrison, Ralf Zimmermann
Vacuum ultraviolet (VUV) absorption spectroscopy was recently introduced as a new detection system for one, as well as comprehensive two-dimensional gas chromatography (GC×GC) and successfully applied to the analysis of various analytes in several matrices. In this study, its suitability for the analysis of breath metabolites was investigated and the impact of a finite volume of the absorption cell and makeup gas pressure was evaluated for volatile analytes in terms of sensitivity and chromatographic resolution...
September 16, 2016: Journal of Chromatography. A
Marco Mattonai, Diego Tamburini, Maria P Colombini, Erika Ribechini
A novel analytical approach based on pyrolysis-gas chromatography coupled with mass spectrometry of carbohydrates with in situ silylation using hexamethyldisilazane is presented in this work for the first time. A micro reaction sampler was used to simultaneously achieve the pyrolyis reaction and facilitate the derivatization of pyrolysis products, by enabling the materials to react with the derivatizing agent in a sealed capsule at high temperature and pressure for long periods of time. This drastically increased the complete silylation of the pyrolysis products and the chromatographic resolution, resulting in less complex pyrograms and increased sensitivity toward the most stable compounds...
September 20, 2016: Analytical Chemistry
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