Hydrocarbons in the banana leaf, Musa sapientum

Mass spectrometry, spectroscopy, and thin layer and gas chromatography studies of hydrocarbons in banana leave

Gas Chromatograph-quadrupole Mass Spectrometric Analysis of Organic Compounds

Gas chromatography and mass spectrometry of acetonitrile, furan, pyrrole, paraffins, and other aromatic organic compounds of biological significanc

Characterization and Quantification of Isoprene-Derived Epoxydiols in Ambient Aerosol in the Southeastern United States

Isoprene-derived epoxydiols (IEPOX) are identified in ambient aerosol samples for the first time, together with other previously identified isoprene tracers (i.e., 2-methyltetrols, 2-methylglyceric acid, C5-alkenetriols, and organosulfate derivatives of 2-methyltetrols). Fine ambient aerosol collected in downtown Atlanta, GA and rural Yorkville, GA during the 2008 August Mini-Intensive Gas and Aerosol Study (AMIGAS) was analyzed using both gas chromatography/quadrupole mass spectrometry (GC/MS) and gas chromatography/time-of-flight mass spectrometry (GC/TOFMS) with prior trimethylsilylation. Mass concentrations of IEPOX ranged from ~1 to 24 ng m^(−3) in the aerosol collected from the two sites. Detection of particle-phase IEPOX in the AMIGAS samples supports recent laboratory results that gas-phase IEPOX produced from the photooxidation of isoprene under low-NO_x conditions is a key precursor of ambient isoprene secondary organic aerosol (SOA) formation. On average, the sum of the mass concentrations of IEPOX and the measured isoprene SOA tracers accounted for about 3% of the organic carbon, demonstrating the significance of isoprene oxidation to the formation of ambient aerosol in this region

Cytochemical studies of planetary microorganisms - Explorations in exobiology Status report, Sep. 1, 1965 - Apr. 1, 1966

Cytochemical studies of planetary microorganisms by fluorometry, gas chromatography and optical resolution, mass spectrometry, computer managed instrumentation, and UV microspectrometr

Mass spectrometry based metabolomics and Lipidomics.

Metabolomics and lipidomics studies are important to understand living organisms at the molecular level. In this dissertation, I conducted various untargeted and targeted metabolomics and lipidomics studies using mass spectrometry based analytical platforms. Firstly, I investigated the androgen depletion effects on fecal metabolites in a mouse model of systemic lupus erythematosus and metabolite biomarkers for colorectal cancer using two-dimensional gas and liquid chromatography-mass spectrometry. Secondly, I investigated the relationship between gut microbiota-mediated resistance and susceptibility to malaria and the production of short-chain fatty acids using gas chromatography-mass spectrometry. Thirdly, I developed a high-throughput liquid chromatography-mass spectrometry method to profile long-chain fatty acids and oxylipins. And finally, I developed a comprehensive two-dimensional liquid chromatography-mass spectrometry method for untargeted lipidomics

Identifying metabolites by integrating metabolome databases with mass spectrometry cheminformatics.

Novel metabolites distinct from canonical pathways can be identified through the integration of three cheminformatics tools: BinVestigate, which queries the BinBase gas chromatography-mass spectrometry (GC-MS) metabolome database to match unknowns with biological metadata across over 110,000 samples; MS-DIAL 2.0, a software tool for chromatographic deconvolution of high-resolution GC-MS or liquid chromatography-mass spectrometry (LC-MS); and MS-FINDER 2.0, a structure-elucidation program that uses a combination of 14 metabolome databases in addition to an enzyme promiscuity library. We showcase our workflow by annotating N-methyl-uridine monophosphate (UMP), lysomonogalactosyl-monopalmitin, N-methylalanine, and two propofol derivatives

GLC analysis of base composition of RNA and DNA hydrolysates

Various methods used for the analysis of the base composition of RNA and DNA hydrolysates are presented. The methods discussed are: (1) ion-exchange chromatography, (2) paper chromatography, (3) paper electrophoresis, (4) thin layer chromatography, (5) paper chromatography and time of flight mass spectrometry, and (6) gas-liquid chromatography. The equipment required and the conditions for obtaining the best results with each method are described

Recent Advances in Gas Chromatography

Gas chromatography is one of the most used analytical techniques in the industry. It is a powerful tool with a wide range of applications. This book presents recent advances in gas chromatography, multidimensional gas chromatography, and gas chromatography mass spectrometry. It also discusses inverse gas chromatography. The main focus is the use of gas chromatography techniques to analyze petroleum fluids, biomass, and ionic liquids in medical and petrochemical industries

Identification of a Widespread Palmitoylethanolamide Contamination in Standard Laboratory Glassware.

Introduction: Fatty acid ethanolamides (FAEs) are a family of lipid mediators that participate in a host of biological functions. Procedures for the quantitative analysis of FAEs include organic solvent extraction from biological matrices (e.g., blood), followed by purification and subsequent quantitation by liquid chromatography-mass spectrometry (LC/MS) or gas chromatography-mass spectrometry. During the validation process of a new method for LC/MS analysis of FAEs in biological samples, we observed unusually high levels of the FAE, palmitoylethanolamide (PEA), in blank samples that did not contain any biological material. Materials and Methods: We investigated a possible source of this PEA artifact via liquid chromatography coupled to tandem mass spectrometry, as well as accurate mass analysis. Results: We found that high levels of a contaminant indistinguishable from PEA is present in new 5.75″ glass Pasteur pipettes, which are routinely used by laboratories to carry out lipid extractions. This artifact might account for discrepancies found in the literature regarding PEA levels in human blood serum and other tissues. Conclusions: It is recommended to take into account this pitfall by analyzing potential contamination of the disposable glassware during the validation process of any method used for analysis of FAEs