Evaluation of reservoir connectivity using whole-oil gas chromatographic fingerprint technology: A case study from the Es_3~3 reservoir in the Nanpu Sag, China

In this study, whole-oil gas chromatographic fingerprint analyses were performed on oils from the Es3^3 reservoir in the Liubei area of the Nanpu Sag. The gas chromatographic peaks of cyclic and branched alkanes with relatively high resolution from nCl0 to nC25 were selected to establish a database of whole-oil gas chromatographic peak height ratio fingerprints. Reservoir fluid connectivity was identified by using clustering analysis. This method can reflect the gas chromatography fingerprint information accurately and entirely, and avoid the one-sidedness of the star diagram method which only selects several fixed gas chromatographic peaks.

An Excellent Gas Chromatographic Stationary Phase for Separation of Phenol and Cresol Isomers--Heptakis(2,6-di-O-pentyl-3-O-allyl)-β-Cyclodextrin

Heptakis(2.6-di-O-pentyl-3-O-ally)-β-cyclodextrin as an excellent gas chromatographic stationary phase separating phenol and cresol isomers is described.

DIFFERENTIATION OF SOME YEAST SPECIES BY CAPILLARY GAS CHROMATOGRAPHIC ANALYSIS OF CELLULAR FATTY ACIDS

The cellular fatty acids from a total of 62 strains of Torulopsis glabrata (T. glabrata), Saccharomyces cerevisiae (S. cerevisiae), Rhodotorula rubra (R. rubra), Candida krusei (C. krusei), Candida albicans (C. albicans) and Candida tropicalis (C. tropicalis) were examined by capillary gas chromatography. On the basis of fatty acid composition, all strains could be differentiated as to species. These results indicate that capillary gas chromatographic analysis of cellular fatty acids is likely to be useful for rapid identification or grouping of newer isolates of yeast species.

Rapid Gas Chromatographic Assay of Diazinon:Application to the Study of Diazinon Kinetics in Rats

A rapid method was developed for the determination of diazinon in plasma using gas chromatography with electron-capture detection (GC-ECD). Following a single extraction with hexane from 100μl of plasma, diazinon was quantitated on a 3% OV-17 column. The detection limit was 10 ng/ml and linearity was obtained in the range of 25 ng/ml-2500 ng/ml.The applicability of the assay to single-dose kinetics in rats is illustrated

Experimental investigation on combustion and unregulated emission characteristics of butanol-isomer/gasoline blends

Effects of butanol isomers on characteristics of combustion and emission were studied on PFI SI engine. Experiments were operated under the condition of 3 and 5 bar brake mean effective pressure (BMEP) engine loads and different equivalence ratios (φ=0.83-1.25) with engine speed of 1200 r/min using blends made of 70 vol.% gasoline and 30 vol.% butanol isomers (N30, S30, I30 and T30). The results indicated that compared with gasoline, all butanol isomer blends have higher cylinder pressure. N30 has the highest and most advanced peak pressure, and T30 shows a higher brake specific fuel consumption (BSFC) and lower brake thermal efficiency (BTE). N30 presents a lower UHC emissions and I30 has slightly higher CO emissions than other blends. For unregulated emissions, compared with gasoline, butanol isomer blends have higher acetaldehyde, and N30 produces a higher emission of 1,3-butadiene than other blends. A reduction in benzene, toluene, ethylbenzene and xylene (BTEX) has been found with butanol isomer blends.

A Study on Microwave Induced Plasma Ionization Detector for Gas Chromatograph

Among various ionization detectors for gas chromatography(GC), the most promising one is perhaps the nonradioactive ionization detector which makes use of a microwave induced plasma(MIP). The use of MIP for gas chromatography was first studied by McCormack, et al. in 1965, Freeman developed a photoionization detector utilizing helium microwave discharge. In 1971, we developed a microwave

Gas Chromatogragh Analysis of Beaver Oil

Eight fatty acids from beaver oil were identified by GC-9A, and their contents were determinded. A simple yet effective method for separation and quantification was described. Contents of the fatty acids were related to their conditions of extraction.

MEDV-13 for QSRR of 62 Polychlorinated Naphthalenes

A molecular electronegativity distance vector based on 13 atomic types (MEDV-13) is used to describe the structures of 62 polychlorinated naphthalene (PCN) congeners and related to the gas chromatographic relative retention indices (RIs) of PCNs. Using multiple linear regression, a 4-variable quantitative structure-retention relationship (QSRR) with the correlation coefficient of estimations (r) being 0.9912 and the root mean square error of estimations (RMSEE) being 31.4 and the correlation coefficient of predictions (q) and the root mean square error of predictions (RMSEP) in the leave-one-out procedure are 0.9898 and 33.76, respectively.

Quick Measurement of CH_4, CO_2 and N_2O Emissions from a Short-Plant Ecosystem

Combining improved injector, gas line and valve-driving models, a gas chromatograph (GC) equipped with Hydrogen Flame Ionization Detector (FID) and Electron Capture Detector (ECD), can measure CH4, CO2, and N2O simultaneously in an air sample in four minutes. Test results show that the system has high sensitivity, resolution, and precision; the linear response range of the system meets the requirement of flux measurements in situ. The system is suitable for monitoring fluxes of the main greenhouse gases in a short-plant field since it is easy to use, efficacious, and constant and reliable in collecting data.

Method for rapid on-site identification of VOCs

Rapid on-site identification of volatile organic compounds （VOCs） in ambient air is an important first step in remediation efforts. This study describes modification of a commercially available, portable GC/MS system and development of an analysis protocol for rapid （〈 3 min） sampling and identification of VOCs typically found at contaminated sites at the low ppbv level.

Genotoxic Effects of PAH Containing Sludge Extracts in Chinese Hamster Ovary Cell Cultures

Objective Many studies have been conducted in order to evaluate the genotoxicity of chemicals and waste materials, which utilized in vivo test protocols. The use of animals for routine toxicity testing is now questioned by a growing segment of society. Methods Keeping the above fact in mind, we have conducted in the present study the genotoxicity evaluation of oily sludge samples generated from a petroleum refinery and petrochemical industry and ETP sludge from petroleum refinery using DNA damage, chromosomal aberration, p53 protein induction and apoptosis in short term in vitro mammalian Chinese Hamster Ovary cell cultures. Results It is evident from the results that the oily sludge compounds derived from petroleum refinery and petrochemical industry could cause DNA damage, chromosomal aberration, p53 protein accumulation and apoptotic cell death on exposure to oily sludge extracts in the presence of metabolic activation system (S-9 mix), however, ETP sludge extract could not cause significant genotoxicity in comparison to oily sludge extract and negative control. Conclusion The effect may be attributed to polycyclic aromatic hydrocarbons present in the samples as evidenced from GC-MS.

Preparation and Uncertainty Assessment of Standard Work Solution of Hexachlorobenzene,Malathion and Sulfotep

[ Objective ] To prepare standard work solution of three pesticides used in the intermediate check of gas chromatograph and evaluate the uncertainty of solution. [ Method ] In view of intermediate check needs of gas chromatograph, common pesticides in pesticide residual test were taken as the study objects, i.e., hexachlorabenzene, malathion and Sulfotep, state pesticide reference materials as the materials, volumetry was applied to prepare standard work solution of pesti- cides. Evenness and stability of the work solution was tested by using gas chromatographs installed with electron capture detector （ECD）, flame photometric detec- tor （FPD） and flame ionization detector （ FID）, respectively, and after the evaluation of concentration, uncertainty of the work solution was assessed from the per- spectives of raw materials, preparation process, evenness and stability. [ Result ] Mass concentrations of the three standard work solution was 0.1 mg/L, 10.0mg/ L, 100.0 mg/L, respectively, and relative expanded uncertainty 2.640%, 1. 980% and 2.400% （ k = 2）. [ Conclusion] The study offers technical support for the intermediate check of laboratory apparatuses.

Application of GC/EIMS in Combination with Semi-Empirical Calculations for Identification and Investigation of Some Volatile Components in Basil Essential Oil

Volatile components in the extracts of basil leaves (Ocimum basilicum L.) were identified by gas chromatography/mass spectrometry (GC/MS) with electron ionization (EI) mode. The major volatile components of basil under investigation are α-pinene, sabinene, β-pinene, d-limonene, eucalyptol, l-linalool and estragole. Electron ionization mass spectra of these compounds have been obtained and investigated. Furthermore, the semi-empirical MNDO [Modified Neglect of Diatomic Overlap] method was used to calculate the thermochemical data for the structural properties of these compounds.

Dynamic Microwave-assisted Extraction Online Coupled with QuEChERS for the Determination of Organophosphorus Pesticides in Cereals by Gas Chromatography

A rapid analytical method was first developed to detect organophosphorus pesticides(OPPs)in cereals,which used dynamic microwave assisted extraction(DMAE)coupled online with a modified quick,easy,cheap,effective,rugged,and safe(QuEChERS)method.Cereals samples were mixed with a certain amount of quartz,Ci8 and the primary second amine(PSA),and extracted successively with the acetonitrile-water solution(80%,VIV)under microwave irradiation.The obtained eluate was directly introduced into a collection tube containing NaCl and MgSO4.Finally,the supemate was evaporated and reconstructed,and determined by gas chromatographic spectrometry.Some factors affecting the experimental results were studied and optimized.The extraction and purification processes were carried out coinstantaneously and 12 samples could be treated in one step in 4 min.Low limits of tection(0.43—1.31 p.g/kg)for OPPs were obtained in cereals.The relative standard deviations(RSDs)were 2.1%—9.3%.The recoveries of OPPs ranged from 76.1%to 100.2%.By combining the advantages of DMAE with QuEChERS,the sample pretreatment process was simple to operate,with little amount of organic solvent.The whole extraction process was completed in a closed environment,therefore it was very appropriate for daily analysis of OPPs in cereals.

Dynamic separation of Xe and Kr by metal-organic framework and covalent-organic materials： a comparison with activated charcoal

We systematically investigate dynamic separation of Xe and Kr at room temperature using four representative porous materials(Cu-BTC, ZIF-8, COP-4 and activated carbon(AC)). Results indicate that among the four materials, Cu-BTC not only shows the highest retention volume per gram(V_g=788 m L g^(-1), which is 1.8 times of activated carbon(436 m L g^(-1))) under flowing condition, but also can separate 350 ppm Xe from 35 ppm Kr mixture in air with a high Xe/Kr selectivity of 8.6 at room temperature and 200 k Pa, due to its suitable pore morphology, open metal sites, small side pockets in the framework. Moreover, the Cu-BTC also performs well on individual separation of Xe, Kr, CO_2 from five-component gas mixture(Xe:Kr:CO_2:Ar:N_2= 1:1:1:1:0.5, V/V) and has the longest retention time for Xe(20 min) in gas chromatographic separation, suggesting that it is a good candidate for potential applications as polymeric sieves.

Applying a new method for direct collection, volume quantification and determination of N_2 emission from water

The emission of N2 is important to remove excess N from lakes, ponds, and wetlands. To investigate the gas emission from water, Gao et al.（2013） developed a new method using a bubble trap device to collect gas samples from waters. However, the determination accuracy of sampling volume and gas component concentration was still debatable. In this study, the method was optimized for in situ sampling, accurate volume measurement and direct injection to a gas chromatograph for the analysis of N2 and other gases. By the optimized new method, the recovery rate for N2 was 100.28% on average; the mean coefficient of determination（R2） was 0.9997; the limit of detection was 0.02%. We further assessed the effects of the new method, bottle full of water, vs. vacuum bag and vacuum vial methods, on variations of N2 concentration as influenced by sample storage times of 1,2, 3, 5, and 7 days at constant temperature of 15°C, using indices of averaged relative peak area（%） in comparison with the averaged relative peak area of each method at 0 day.The indices of the bottle full of water method were the lowest（99.5%–108.5%） compared to the indices of vacuum bag and vacuum vial methods（119%–217%）. Meanwhile, the gas chromatograph determination of other gas components（O2, CH4, and N2O） was also accurate. The new method was an alternative way to investigate N2 released from various kinds of aquatic ecosystems.