ChemInform Abstract: DETERMINATION OF EXCESS VOLUMES IN 1,2-DICHLOROETHANE + BENZENE, + TOLUENE, + P-XYLENE, + CYCLOHEXANE, AND + METHYLCYCLOHEXANE WITH A VIBRATING-TUBE DENSIMETER

1978 ◽  
Vol 9 (31) ◽  
Author(s):  
E. WILHELM ◽  
J.P.E. GROLIER ◽  
M. H. K. GHASSEMI
Keyword(s):  
Excess Volumes ◽  
Benzene Toluene ◽  
Vibrating Tube Densimeter

Excess volumes and refractive indices in the benzene-tert-amyl methyl ether and cyclohexane-tert-amyl methyl ether systems at 298.15 K

1987 ◽  
Vol 52 (12) ◽  
pp. 2839-2843 ◽  
Author(s):  
Jan Linek
Keyword(s):  
Methyl Ether ◽  
Excess Molar Volumes ◽  
Excess Volumes ◽  
Refractive Indices ◽  
Molar Volumes ◽  
Vibrating Tube Densimeter ◽  
Ether System

Excess molar volumes in the benzene-tert-amyl methyl ether and cyclohexane-tert-amyl methyl ether systems were measured by a vibrating-tube densimeter at 298.15 K and compared with the data for the methanol-tert-amyl methyl ether system determined previously. Besides, the refractive indices in both the systems were measured at the same temperature.

scholarly journals Airborne determination of the temporo-spatial distribution of benzene, toluene, nitrogen oxides and ozone in the boundary layer across Greater London, UK

2015 ◽  
Vol 15 (9) ◽  
pp. 5083-5097 ◽  
Author(s):  
M. D. Shaw ◽  
J. D. Lee ◽  
B. Davison ◽  
A. Vaughan ◽  
R. M. Purvis ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Nitrogen Oxides ◽  
Linear Regression Analysis ◽  
Proton Transfer Reaction ◽  
Mixing Ratios ◽  
Spatially Resolved ◽  
Dual Channel ◽  
Benzene Toluene

Abstract. Highly spatially resolved mixing ratios of benzene and toluene, nitrogen oxides (NOx) and ozone (O3) were measured in the atmospheric boundary layer above Greater London during the period 24 June to 9 July 2013 using a Dornier 228 aircraft. Toluene and benzene were determined in situ using a proton transfer reaction mass spectrometer (PTR-MS), NOx by dual-channel NOx chemiluminescence and O3 mixing ratios by UV absorption. Average mixing ratios observed over inner London at 360 ± 10 m a.g.l. were 0.20 ± 0.05, 0.28 ± 0.07, 13.2 ± 8.6, 21.0 ± 7.3 and 34.3 ± 15.2 ppbv for benzene, toluene, NO, NO2 and NOx respectively. Linear regression analysis between NO2, benzene and toluene mixing ratios yields a strong covariance, indicating that these compounds predominantly share the same or co-located sources within the city. Average mixing ratios measured at 360 ± 10 m a.g.l. over outer London were always lower than over inner London. Where traffic densities were highest, the toluene / benzene (T / B) concentration ratios were highest (average of 1.8 ± 0.5 ppbv ppbv-1), indicative of strong local sources. Daytime maxima in NOx, benzene and toluene mixing ratios were observed in the morning (~ 40 ppbv NOx, ~ 350 pptv toluene and ~ 200 pptv benzene) and in the mid-afternoon for ozone (~ 40 ppbv O3), all at 360 ± 10 m a.g.l.

Determination of the Stoichiometry of the Adducts Formed between some Heterocyclic Bases and Copper(II) Bis(diethyldithiocarbamate) in Various Solvents

1973 ◽  
Vol 51 (10) ◽  
pp. 1530-1534 ◽  
Author(s):  
J. B. Farmer ◽  
F. G. Herring ◽  
R. L. Tapping
Keyword(s):  
Electron Paramagnetic Resonance ◽  
Paramagnetic Resonance ◽  
Benzene Toluene ◽  
Heterocyclic Bases ◽  
Electron Paramagnetic

The stoichiometry of the adducts formed between copper(II) bis(diethyldithiocarbamate) and pyridine in benzene, toluene, and chloroform and between 3-picoline, 4-picoline, and 3,4-lutidine in benzene are shown to be 1:1. The method employed is that of Scatchard using electron paramagnetic resonance studies.

scholarly journals DETERMINATION OF BTEX IN ENVIRONMENTAL SAMPLES: DEVELOPMENT AND PROTECTION OF TECHNOLOGIES AND ANALYTICAL METHODS

2019 ◽  
Vol 16 (31) ◽  
pp. 431-439
Author(s):  
Helilma de Andréa PINHEIRO ◽  
Ana Paula Mota FERREIRA ◽  
Ismael Carlos Braga ALVES ◽  
Antônio Fernandes SANTOS JÚNIOR ◽  
Raquel Bezerra dos Santos SAWCZUK ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Environmental Samples ◽  
Low Cost ◽  
The United States ◽  
Operational Control ◽  
Toxic Compounds ◽  
Chromatographic Techniques ◽  
Benzene Toluene ◽  
And Storage

The contamination of water and soil by petroleum hydrocarbons is reported quite frequently, mainly due to accidents involving transport and storage of fuels. Among the most toxic compounds the most volatile benzene, toluene, ethylbenzene and xylene (BTEX). Residues of these compounds can cause serious environmental and public health troubles. Thus, more sensitive, selective and low-cost techniques, focused on the analysis and monitoring of these contaminants are being developed in order to establish operational control and to comply with local laws, but the intellectual property of such technologies is still unknown. The present study shows the panorama about patents, thesis and dissertations which have been already published on this theme. Together, the United States and China hold the largest number of patents, and most of thesis/dissertations describe methodologies for BTEX detection in water, although numerous environmental problems caused by oils in the soil had been reported. Also, the methods based on chromatographic techniques stand out in relation to the other techniques. It was possible to verify important advances in the field of sensors, especially the electrochemical ones, in order to solve the analytical gaps.

scholarly journals Identification and quantification of organic pollutants in the air of the city of Astana using solid phase microextraction

2017 ◽  
pp. 14-17
Author(s):  
Dina Orazbayeva ◽  
Ulzhalgas Karatayeva ◽  
Kulzhan Beysembayeva ◽  
Kulyash Meyramkulova
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Ambient Air ◽  
Average Concentration ◽  
Polycyclic Aromatic ◽  
Benzene Toluene ◽  
The City

Solid-phase microextraction in combination with gas chromatography and mass-spectrometry (GC-MS) was used for determination of benzene, toluene, ethylbenzene and o-xylene (BTEX), polycyclic aromatic hydrocarbons (PAH), and for identification of volatile organic compounds (VOCs) in ambient air of the city of Astana, Kazakhstan. The screening of the samples showed the presence of mono- and polycyclic aromatic hydrocarbons, alkanes, alkenes, phenols, and benzaldehydes. The concentrations of naphthalene were 5-7 times higher than the permissible value, it was detected in all studied air samples. Average concentration of naphthalene was 18.4 μg/m3, acenaphthylene – 0.54 μg/m3, acenaphthene – 1.63 μg/m3, fluorene – 0.79 μg/m3, anthracene – 3.27 μg/m3, phenanthrene – 0.22 μg/m3, fluorantene – 0.74 μg/m3, pyrene – 0.73 μg/m3. Average concentrations of BTEX in the studied samples were 31.1, 84.9, 10.8 and 11.6 μg/m3, respectively. Based on the statistical analysis of the concentrations of BTEX and PAH, the main source of city air pollution with them was assumed to be vehicle emissions.

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