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"Basic gas chromatography", Third Edition, provides a brief introduction to GC following the objectives for titles in this series. It should appeal to readers with varying levels of education and emphasizes a practical, applied approach to the subject. : This book provides a quick need-to-know introduction to gas chromatography; still the most widely used instrumental analysis technique, and is intended to assist new users in gaining understanding quickly and as a quick reference for experienced users.The new edition provides updated chapters that reflect changes in technology and methodology, especially sample preparation, detectors and multidimensional chromatography. The book also covers new detectors recently introduced and sample preparation methods that have become much more easily accessible since the previous edition.

Gas chromatography. --- Chromatographie en phase gazeuse.

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Chemical laboratory practice --- laboratoria chemie --- LC (liquid chromatography) --- chromatografie --- GC (gas chromatography) --- HPLC (high power liquid chromatography) --- enzymen

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Comprehensive two-dimensional gas chromatography (GC×GC) coupled to high-resolution time-of-flight mass spectrometer (HRTOFMS) has been used to perform non-recreational cannabis strains differentiation. The sampling method, based on dynamic headspace and thermal desorption (TD), has been optimized to maximize volatile organic compound (VOC) collection. Volatile profiles of nine cannabis flowers were collected at room temperature using thermal desorption tubes. Terpenes and other specific volatile compounds emitted by the flowers have been used through advanced data analysis. Different data pre-treatments have been investigated on raw data prior to statistical analysis. Principal component analysis (PCA) has been used to visualize the impact of pre-processing. Based on the selected data treatment, five strains out of the nine were selected for strain differentiation. Furthermore, the global chemical classes repartition, odor profile, and medical effects of strains were investigated. Major compounds listed in literature have been successfully identified by the HRTOFMS, using the combination of specific fragmentation and high mass accuracy to increase the confidence in compounds identification. In conclusion, strains have been separated upon PCA results, which has shown also its potential to differentiate cannabis subspecies. Moreover, compound investigation has shown similar profile of aromas with different major flavors in different strains and has shown different medical compound amounts proving the medical potential of cannabis-based products uses. La chromatographie en phase gazeuse bidimensionnelle (GC×GC) couplée à la spectrométrie de masse à temps de vol à haute résolution (HRTOFMS) a été utilisée pour différencier des fleurs de cannabis à usage non-récréatif. La méthode d’échantillonnage, basée sur l’échantillonnage dynamique de l’espace de tête et sur la désorption thermique (TD), a été optimisée afin de maximiser la collection de composés organiques volatils (COVs). Les COVs de neuf fleurs de cannabis ont été récoltés à température ambiante à l’aide de tubes de désorption thermique. L’analyse des données s’est basée sur le profil des terpènes et autres composés volatils des fleurs. Des pré-traitements des données ont été effectués avant leurs analyses statistiques. L’analyse par composante principale (ACP) a été utilisée afin de visualiser l’impact du pré-traitement sur les données. A partir des données sélectionnées après le pré-traitement, cinq fleurs sur les neufs ont été sélectionnées en vue de les différencier. La répartition globale des classes de composés chimiques, le profil des odeurs et des effets médicaux des fleurs ont également été étudiés. Les composés majeurs référencés dans la littérature ont été identifiés par la HRTOFMS qui confère une haute précision de la masse et une plus grande certitude dans l’identification des composés. En conclusion, les fleurs ont été séparées selon leurs résultats d’ACP. Celle-ci a montré son potentiel pour différencier les sous-espèces de cannabis. De plus, l’analyse des composés a montré des profils d’odeurs similaires, avec des arômes majoritaires dans les différentes fleurs. Elle a aussi montré la présence de composés médicinaux, montrant le potentiel médical des produits basés sur le cannabis.

Comprehensive two-dimensional gas chromatography --- Cannabis --- Volatile organic compounds --- Thermal desorption --- High resolution time-of-flight mass spectroscopy --- Chromatographie gazeuse bidimensionnelle --- Cannabis --- Désorption thermique --- Spectroscopie de masse à temps de vol à haute résolution --- Composés organiques volatils --- Physique, chimie, mathématiques & sciences de la terre > Chimie

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Focuses on so-called 'hyphenated techniques' (EGA-TGA, TGA-GC/MS, etc), which allow a great deal of chemical information about a sample to be revealed quickly and conveniently. The methods are highly applicable to polymer/plastics samples, but also to other materials including pharmaceuticals, biomass, and various organic and inorganic compounds.

Gases --- Gas. --- Gas chromatography. --- Infrared spectroscopy. --- Mass spectrometry. --- Thermal analysis. --- Thermogravimetry. --- Analysis. --- Thermal gravimetric analysis --- Gravimetric analysis --- Thermal analysis --- Differential thermal analysis --- Differential thermal curves --- Analytical chemistry --- Mass spectra --- Mass spectrograph --- Mass spectroscopy --- Mass spectrum analysis --- Mass (Physics) --- Nuclear spectroscopy --- Spectrum analysis --- Infra-red spectrometry --- Infrared spectrometry --- Spectrometry, Infrared --- Spectroscopy, Infrared --- Optical spectroscopy --- Gas-liquid chromatography --- GLC (Chromatographic analysis) --- Vapor-phase chromatography --- Chromatographic analysis --- Coal-gas --- Illuminating gas --- Producer gas --- Gases, Asphyxiating and poisonous --- Coal-tar products --- Distillation, Destructive --- Eudiometry --- Gas --- Gas analysis --- Gasometry --- Analysis

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Sterols and other isoprenoids are of great interest for their molecular structure and function in cell architecture and evolution, as well as for their importance in medicine and agriculture. Molecules’ 2019 Festschrift Special Issue in honor of the 65th birthday of Prof. W. David Nes, an internationally recognized chemical biologist and recipient of the George Schroepher medal for sterol research, focuses on recent developments in the chemistry, biosynthesis, and function of these polycyclic natural products. This volume of Molecules contains 16 leading-edge review articles and original research contributions from an international cast of scientists. This volume is grouped into three sections: (i) isoprenoid metabolome and diversity, (ii) clinical evaluation of sterol and triterpene structures and biosynthesis, and (iii) methods and synthesis of steroids and other compounds. The volume will be a valuable reference tool for those who study medicinal chemistry, protein chemistry, and biochemistry of isoprenoid lipids.

high-fat high-carbohydrate diet --- toxicity --- oxysterol --- n/a --- squalene cyclase --- sterol content --- sterolomics --- Polystichum --- Smith-Lemli-Opitz syndrome --- antifungals --- alkaloid --- cycloartenol synthase --- degeneration --- phytosterol --- Rhizopus arrhizus --- fibroblasts --- pod-blast --- fern --- cholesterol --- cytotoxic activity --- N-methylpiperidine. reductive deamination --- genetic disease --- isoprenoid --- steroid --- atherosclerosis --- granatane --- antioxidant --- wound healing --- development --- enzyme-assisted derivatization --- maturity --- terpene --- keratinocytes --- C4-demethylation complex (C4DMC) --- ?-sitosterol --- mesocarp --- sterol biosynthesis --- mechanism-based inactivators --- Mucorales --- gas chromatography-mass spectrometry (GC-MS) --- Girard reagent --- ROS --- sterol pattern --- N-methylcadaverine --- ?-tocopherol --- electrospray ionization-mass spectrometry --- human African trypanosomiasis --- HUVECs --- lipidomics --- campesterol --- triterpene --- oxyphytosterol --- leishmania --- Chagas disease --- LOX-1 --- sterol C24-methyltransferase --- antifungal effectivity --- ergosterol biosynthesis --- hormone --- glucose homeostasis --- retina --- solanaceae --- cholestanoic acid --- algal sterols --- cell migration --- withanolides --- insulin resistance --- Zingiber officinale --- posaconazole --- synthesis --- pre-diabetes --- pharmacognosy --- sterol --- 4-methylsterol --- oleanolic acid --- antiparasitic drugs --- lupeol --- oilseed --- aurelianolides --- divalent metal co-factor ligation --- bile alcohol --- phytosterols --- azoles --- infectious disease --- gingerols --- UV-radiation --- oil bodies --- ZnO --- sterol 14?-demethylase --- stigmasterol