Gas chromatographic analysis of petroleum associated condensate oil with simultaneous determination of some characteristic physical parameters

A method is developed for the analysis of associated condensate by capillary gas chromatography (GC) with simultaneous determination of its major physical characteristic parameters. The method aims at the qualitative and quantitative determination of C(2)-C(36) alkanes, methylcyclopentane, cyclohexane, methylcyclohexane, benzene, toluene, ethylbenzene, xylenes, and 1,2,4-trimethylbenzene. This composition is according to the petroleum companies demand. The method is used for the simultaneous determination of the condensate average molecular weight, density, carbon-to-hydrogen ratio, and boiling range. The data obtained by the method has a good agreement with those obtained by other methods. The literature methods cited later used a simulated distillation method to obtain the hydrocarbon distribution spectrum of the given condensate sample. The obtained results revealed that the GC capillary method used is most rapid and accurate for achieving the demanded analytical report.     

Thermogravimetric analysis of teeth for forensic purposes

Journal of Thermal Analysis and Calorimetry - The objectives of this study were to characterize the thermal decomposition of human teeth and to evaluate the decomposition of organic matter,...     

Gas chromatographic determination of propyphenazone in plasma

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Combined immunological and thin-layer chromatographic method of the determination of morphine

     

Gas chromatographic determination of xanthinol in plasma

The determination of xanthinol in plasma is described. After extraction of the drug, together with the internal standard (papaverine hydrochloride), the extract is evaporated to dryness and the drug is derivatized with acetic anhydride for chromatography. The method is linear for 2–100μg ml^-1 ; the coefficient of variation is 3% and the recovery 80%. The resulting stable solution allows large numbers of samples to be processed with an automatic injector.     

Gas chromatographic determination of impurities in nitromethane

Summary Impurities in commercially available nitromethane have been determined by gas-liquid chromatography using six different column packings. Besides nitromethane, 1-nitropropane, 2-nitropropane, acetonitrile, methanol, small amounts of ethanol and acetaldehyde have been detected. The presence of formaldehyde, ethyl acetate and acetone is probable. Mixtures containing comparable amounts of the four nitroalkanes could be separated on all columns, but plots of logarithms of the retention times vs. carbon number or boiling points of the nitroalkanes or column temperatures were linear only in case of columns packed with Porapak R and Q.     

Gas chromatographic determination of micro-amounts of cyclamates.

It was found that triethylammonium cyclamate is converted into N-hepta-fluorobutyrylcyclohexylamine in a high and constant yield by reaction with hepta-fluorobutyric anhydride at 90 degrees for 1 h, and gas chromatography of the product gives a sharp peak that is highly sensitive to an electron capture detector. A useful method for the micro-determination of cyclamates was established by combining this reaction with gas chromatography.     

Gas chromatographic determination of benzothiophenes in high-purity sulfur

A procedure is developed for the determination of benzothiophene, dibenzothiophene, and 4,6-dimethyldibenzothiophene in high-purity sulfur, including liquid-phase microextraction preconcentration, identification by gas chromatography?mass spectrometry, and gas chromatographic determination with flame photometric detection. The rate of microextraction recovery was from 16 to 78%. The limits of detection were 8 × 10^–5 wt % for benzophiophene and 2 × 10^–5 wt % for dibenzothiophene and 4,6-dimethyldibenzothiophene.