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Gass chromatography

Stefano Catola, Srikanta Dani Kaidala Ganesha, Luca Calamai, Francesco Loreto, Annamaria Ranieri, Mauro Centritto
Dimethylsulfoniopropionate (DMSP) and dimethyl sulphide (DMS) are compounds found mainly in marine phytoplankton and in some halophytic plants. DMS is a globally important biogenic volatile in regulating of global sulfur cycle and planetary albedo, whereas DMSP is involved in the maintenance of plant-environment homeostasis. Plants emit minute amounts of DMS compared to marine phytoplankton and there is a need for hypersensitive analytic techniques to enable its quantification in plants. Solid Phase Micro Extraction from Head Space (HS-SPME) is a simple, rapid, solvent-free and cost-effective extraction mode, which can be easily hyphenated with GC-MS for the analysis of volatile organic compounds...
2016: Frontiers in Plant Science
Angela Gasse, Heidi Pfeiffer, Helga Köhler, Jennifer Schürenkamp
The aim of this work was to develop and validate a solid-phase extraction (SPE) method for the analysis of cannabinoids with emphasis on a very extensive and effective matrix reduction in order to ensure constant good results in selectivity and sensitivity regardless of the applied measuring technology. This was obtained by the use of an anion exchange sorbent (AXS) and the purposive ionic interaction between matrix components and this sorbent material. In a first step, the neutral cannabinoids ∆9-tetrahydrocannabinol (THC) and 11-hydroxy-∆9-tetrahydrocannabinol (11-OH-THC) were eluted, leaving 11-nor-9-carboxy-∆9-tetrahydrocannabinol (THC-COOH) and the main interfering matrix components bound to the AXS...
July 2016: International Journal of Legal Medicine
Hassan Sadraei, Gholamreza Asghari, Mahdi Alipour
Pycnocycla caespitosa is an essential oil-containing plant naturally growing in southwest of Iran. The extract of this plant has been used as remedy in traditional medicine. Another species of Pycnocyla (P. spinosa) possessed antispasmodic activity. The pharmacological objective of this study was to look for relaxant effect of hydroalcoholic extract and essential oil of P. caespitosa on rat isolated ileum contractions for comparison with loperamide. The essential oil and the hydroalcoholic extract were prepared by hydrodistillation and percolation techniques, respectively...
January 2016: Research in Pharmaceutical Sciences
Michael J Samide, Gregory D Smith
Construction materials used in museums for the display, storage, and transportation of artwork must be assessed for their tendency to emit harmful pollution that could potentially damage cultural treasures. Traditionally, a subjective metals corrosion test known as the Oddy test has been widely utilized in museums for this purpose. To augment the Oddy test, an instrumental sampling approach based on evolved gas analysis (EGA) coupled to gas chromatography (GC) with mass spectral (MS) detection has been implemented for the first time to qualitatively identify off-gassed pollutants under specific conditions...
December 24, 2015: Journal of Chromatography. A
Roelof Oosting, Rogier van der Hulst, Leo Peschier, Miranda Verschraagen
INTRODUCTION: Toxicological findings in deaths by asphyxiation due to a pure inert gas like helium are rare. We present three suicide cases of asphyxial death attributed to anoxia caused by inhalation of helium in a plastic bag positioned over the head. METHODS: In one case, lung tissue, brain tissue and heart blood were obtained during standard autopsy procedures. In two cases, samples were obtained differently: heart blood, femoral blood, brain tissue, lung tissue and/or air from the lungs were directly sealed into headspace vials during autopsy...
November 2015: Forensic Science International
Chandra Bala, Jeffrey Shi, Kerrie Meades
PURPOSE: To transect intraocular lenses (IOLs) using a femtosecond laser in cadaveric human eyes. To determine the optimal in vitro settings, to detect and characterize gasses or particles generated during this process. METHODS: A femtosecond laser was used to transect hydrophobic and hydrophilic acrylic lenses. The settings required to enable easy separation of the lens fragment were determined. The gasses and particles generated were analysed using gas chromatography mass spectrometer (GC-MS) and total organic carbon analyzer (TOC), respectively...
June 2015: Translational Vision Science & Technology
Rajeeva Gaur, Soni Tiwari
BACKGROUND: The rising concerns about the scarcity of fossil fuels, the emission of green house gasses and air pollution by incomplete combustion of fossil fuel have also resulted in an increasing focus on the use of cellulases to perform enzymatic hydrolysis of the lignocellulosic materials for the generation of bioethanol. The aim of this study was to isolate a potential thermo-solvent tolerant cellulase producing bacterium from natural resources, and then applied for purification and characterization...
2015: BMC Biotechnology
Kenneth W Fent, Douglas E Evans, Donald Booher, Joachim D Pleil, Matthew A Stiegel, Gavin P Horn, James Dalton
Firefighters' personal protective equipment (PPE) ensembles will become contaminated with various compounds during firefighting. Some of these compounds will off-gas following a response, which could result in inhalation exposure. This study was conducted to determine the magnitude and composition of volatile organic compounds (VOCs) generated during controlled structure burns that subsequently off-gassed from the firefighters' PPE, and were systemically absorbed and exhaled in firefighters' breath. Three crews of five firefighters performed entry, suppression, and overhaul during a controlled burn...
2015: Journal of Occupational and Environmental Hygiene
Ling Bai, Jonathan Smuts, Phillip Walsh, Hui Fan, Zacariah Hildenbrand, Derek Wong, David Wetz, Kevin A Schug
The analysis of complex mixtures of permanent gases consisting of low molecular weight hydrocarbons, inert gases, and toxic species plays an increasingly important role in today's economy. A new gas chromatography detector based on vacuum ultraviolet (VUV) spectroscopy (GC-VUV), which simultaneously collects full scan (115-240 nm) VUV and UV absorption of eluting analytes, was applied to analyze mixtures of permanent gases. Sample mixtures ranged from off-gassing of decomposing Li-ion and Li-metal batteries to natural gas samples and water samples taken from private wells in close proximity to unconventional natural gas extraction...
April 3, 2015: Journal of Chromatography. A
Rafaela Martin, Jennifer Schürenkamp, Angela Gasse, Heidi Pfeiffer, Helga Köhler
A method for the simultaneous extraction of the hallucinogens psilocin, bufotenine, lysergic acid diethylamide (LSD) as well as iso-LSD, nor-LSD and O-H-LSD from hair with hydrochloride acid and methanol is presented. Clean-up of the hair extracts is performed with solid phase extraction using a mixed-mode cation exchanger. Extracts are measured with liquid chromatography coupled with electrospray tandem mass spectrometry. The method was successfully validated according to the guidelines of the 'Society of Toxicological and Forensic Chemistry' (GTFCh)...
March 2015: Journal of Analytical Toxicology
Ulrik H Mistarz, Jeffery M Brown, Kim F Haselmann, Kasper D Rand
Gas-phase hydrogen/deuterium exchange (HDX) is a fast and sensitive, yet unharnessed analytical approach for providing information on the structural properties of biomolecules, in a complementary manner to mass analysis. Here, we describe a simple setup for ND3-mediated millisecond gas-phase HDX inside a mass spectrometer immediately after ESI (gas-phase HDX-MS) and show utility for studying the primary and higher-order structure of peptides and proteins. HDX was achieved by passing N2-gas through a container filled with aqueous deuterated ammonia reagent (ND3/D2O) and admitting the saturated gas immediately upstream or downstream of the primary skimmer cone...
December 2, 2014: Analytical Chemistry
Kohei Nishiguchi, Keisuke Utani, Detlef Gunther, Masaki Ohata
A novel gas to particle conversion-gas exchange technique for the direct analysis of metal carbonyl gas by inductively coupled plasma mass spectrometry (ICPMS) was proposed and demonstrated in the present study. The technique is based on a transfer of gas into particle, which can be directly analyzed by ICPMS. Particles from metal carbonyl gases such as Cr(CO)6, Mo(CO)6, and W(CO)6 are formed by reaction with ozone (O3) and ammonium (NH3) gases within a newly developed gas to particle conversion device (GPD)...
October 21, 2014: Analytical Chemistry
Kenneth W Fent, Judith Eisenberg, John Snawder, Deborah Sammons, Joachim D Pleil, Matthew A Stiegel, Charles Mueller, Gavin P Horn, James Dalton
Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination...
August 2014: Annals of Occupational Hygiene
William Kranz, Kelley Kitts, Nicholas Strange, Joshua Cummins, Erica Lotspeich, John Goodpaster
In efforts to locate hidden explosives, humans have had few allies as valuable as the explosives-detecting canine. The unrivaled sensitivity and selectivity of the canine nose have combined to make these animals an attractive choice for law enforcement, military, and private security applications. Although the efficacy of trained detector dogs is well-established, the question of which chemical compounds are responsible for causing a dog to recognize a particular odor and alert to it remains a subject of debate for several explosive formulations--including, perhaps most notably, Composition C-4...
March 2014: Forensic Science International
Ricardo H M Godoi, Ana F L Godoi, Sérgio J Gonçalves Junior, Sarah L Paralovo, Guilherme C Borillo, Cybelli Gonçalves Gregório Barbosa, Manoela G Arantes, Renata C Charello, Nelson A Rosário Filho, Marco T Grassi, Carlos I Yamamoto, Sanja Potgieter-Vermaak, Giuliana G Rotondo, Karolien De Wael, Rene van Grieken
The mitigation of pollution released to the environment originating from the industrial sector has been the aim of all policy-makers and its importance is evident if the adverse health effects on the world population are considered. Although this concern is controversial, petroleum refinery has been linked to some adverse health effects for people living nearby. Apart from home, school is the most important indoor environment for children and there is increasing concern about the school environment and its impact on health, also in developing countries where the prevalence of pollution is higher...
October 1, 2013: Science of the Total Environment
Sarah E Lee, Shawn F Bairstow, Jane O Werling, Mahesh V Chaubal, Lawrence Lin, Mary Ann Murphy, James P DiOrio, Jerome Gass, Barrett Rabinow, Xiaoen Wang, Yong Zhang, Zhijian Yang, Robert M Hoffman
OBJECTIVE: The purpose of this work was to prepare a stable paclitaxel nanosuspension and test it for potential use as a targeted chemotherapeutic. Different particle coatings were employed to assess their impact on cellular uptake in vitro. In vivo work was then performed to demonstrate efficacy in tumor-bearing mouse models. MATERIALS AND METHOD: Paclitaxel nanosuspensions were prepared using a homogenization process and coated with excipients. Surface charge was measured by zeta potential, potency by high-performance liquid chromatography, and solubility using an in-line UV probe...
June 2014: Pharmaceutical Development and Technology
Ali S Alfazari, Bayan Al-Dabbagh, Saeeda Almarzooqi, Alia Albawardi, Abdul-Kader Souid
BACKGROUND: The aim of this study was to develop liver tissue preparation suitable for investigating toxins. Hepatocyte respiration, ATP content, urea synthesis, caspase activity and morphology were measured as a function of in vitro incubation time. Mice were anesthetized by sevoflurane inhalation. Small liver fragments were then rapidly excised and incubated at 37°C in Krebs-Henseleit buffer (continuously gassed with 95% O2: 5% CO2) for up to 6 h. Phosphorescence O2 analyzer was used to determine the rate of cellular mitochondrial O2 consumption (kc, μM O2 min-1 mg-1)...
2013: BMC Research Notes
Ahmed R Alsuwaidi, Mohammed T Alsamri, Ali S Alfazari, Saeeda Almarzooqi, Alia Albawardi, Aws R Othman, Thachillath Pramathan, Stacey M Hartwig, Steven M Varga, Abdul-Kader Souid
BACKGROUND: This study aimed to establish a suitable in vitro system for investigating effects of respiratory pathogens and toxins on lung tissue bioenergetics (cellular respiration and ATP content) and caspase activity. Wistar rats and C57Bl/6 mice were anesthetized by sevoflurane inhalation. Lung fragments were then collected and incubated at 37°C in a continuously gassed (with 95% O2:5% CO2) Minimal Essential Medium (MEM) or Krebs-Henseleit buffer. Phosphorescence O2 analyzer that measured dissolved O2 concentration as a function of time was used to monitor the rate of cellular mitochondrial O2 consumption...
2013: BMC Research Notes
Rafaela Martin, Jennifer Schürenkamp, Angela Gasse, Heidi Pfeiffer, Helga Köhler
A validated method for the simultaneous determination of psilocin, bufotenine, lysergic acid diethylamide and its metabolites in serum, plasma and urine using liquid chromatography-electrospray ionization/tandem mass spectrometry was developed. During the solid-phase extraction procedure with polymeric mixed-mode cation exchange columns, the unstable analytes were protected by ascorbic acid, drying with nitrogen and exclusion of light. The limits of detection and quantitation for all analytes were low. Recovery was ≥86 % for all analytes and no significant matrix effects were observed...
May 2013: International Journal of Legal Medicine
Cristina López Cadenas, Nélida Fernández Martínez, Matilde Sierra Vega, Maria J Diez Liébana, Jose M Gonzalo Orden, Ana M Sahagún Prieto, Juan J García Vieitez
OBJECTIVE: To determine the tissue distribution of enrofloxacin after intramammary or simulated systemic administration in isolated perfused sheep udders by measuring its concentration at various sample collection sites. SAMPLE: 26 udders (obtained following euthanasia) from 26 healthy lactating sheep. PROCEDURES: For each isolated udder, 1 mammary gland was perfused with warmed, gassed Tyrode solution. Enrofloxacin (1 g of enrofloxacin/5 g of ointment) was administered into the perfused gland via the intramammary route or systemically via the perfusion fluid (equivalent to a dose of 5 mg/kg)...
November 2012: American Journal of Veterinary Research
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