scholarly journals The Influence of the Concentration of Cyclohexane Radicals Bonded with an Si100 Silica Gel Surface upon the Retention of Some Hydrocarbons in Gas Chromatography

2000 ◽  
Vol 18 (1) ◽  
pp. 43-53 ◽  
Author(s):  
R. Nasuto
Keyword(s):  
Gas Chromatography ◽  
Silica Gel ◽  
Stationary Phases ◽  
Ethyl Benzene ◽  
Polar Organic Compounds ◽  
Phase Concentration ◽  
Bonded Phase ◽  
Unmodified Silica ◽  
Benzene Toluene ◽  
Ethylene Chloride

Four adsorbents based on silica gel Si100 with chemically bonded cyclohexane have been prepared as stationary phases for gas chromatography. The concentrations of cyclohexane radicals thus bonded with the silica gel surface were 1.35, 3.35, 4.17 and 6.02 μmol/m2, respectively. Separation of aliphatic (C6–C12), aromatic (benzene, toluene and m-xylene) and some polar organic compounds (chloroform, ethylene chloride, chlorobenzene, p-chlorotoluene and ethyl benzene) by gas chromatography using columns packed with the prepared adsorbents was studied. It was concluded that the retention of some compounds was increased on the column packed with an adsorbent of 1.35 μmol/m2 concentration relative to that measured on the column packed with the unmodified silica gel. On columns packed with adsorbents with a higher bonded phase concentration than 1.35 μmol/m2, the retention times of all the compounds studied chromatographically decreased with an increase in the bonded phase concentration.

scholarly journals The impact of monoaromatic hydrocarbons on OH reactivity in the coastal UK boundary layer and free troposphere

2014 ◽  
Vol 14 (13) ◽  
pp. 6677-6693 ◽  
Author(s):  
R. T. Lidster ◽  
J. F. Hamilton ◽  
J. D. Lee ◽  
A. C. Lewis ◽  
J. R. Hopkins ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Gas Chromatography ◽  
Atmospheric Chemistry ◽  
Marine Boundary Layer ◽  
Ethyl Benzene ◽  
Free Troposphere ◽  
Flight Mass Spectrometry ◽  
Benzene Toluene ◽  
The Uk ◽  
The Impact

Abstract. Reaction with the hydroxyl radical (OH) is the dominant removal mechanism for virtually all volatile organic compounds (VOCs) in the atmosphere; however, it can be difficult to reconcile measured OH reactivity with known sinks. Unresolved higher molecular weight VOCs contribute to OH sinks, of which monoaromatics are potentially an important sub-class. A method based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC × GC-TOFMS) has been developed that extends the degree with which larger VOCs can be individually speciated from whole air samples (WAS). The technique showed excellent sensitivity, resolution and good agreement with an established gas chromatography–flame ionisation (GC-FID) method, for compounds amenable to analysis on both instruments. Measurements have been made of VOCs within the UK east coast marine boundary layer and free troposphere, using samples collected from five aircraft flights in winter 2011. Ten monoaromatic compounds with an array of different alkyl ring substituents have been quantified, in addition to the simple aromatics, benzene, toluene, ethyl benzene and Σm- and p-xylene. These additional compounds were then included in constrained box model simulations of atmospheric chemistry occurring at two UK rural and suburban field sites in order to assess the potential impact of these larger monoaromatics species on OH reactivity; they have been calculated to contribute an additional 2–6% to the overall modelled OH loss rate, providing a maximum additional OH sink of ~0.9 s−1.

scholarly journals Identifikasi Senyawa BTEX pada Asap Kendaraan Bermotor Roda Dua

2020 ◽  
Vol 9 (2) ◽  
pp. 71-83
Author(s):  
YUSUF EKA MAULANA ◽  
TRISNA YULIANA ◽  
AINI ASPIATI ROHMAH
Keyword(s):  
Gas Chromatography ◽  
Motor Vehicle ◽  
Strong Relationship ◽  
Ethyl Benzene ◽  
Mass Spectrometers ◽  
Measurement Results ◽  
Benzene Toluene ◽  
Motorized Vehicles ◽  
Hazardous Compounds ◽  
Btex Compounds

 AbstrakPenggunaan kendaraan bermotor roda dua di Indonesia semakin berkembang pesat. Semakin tinggi tingkat penggunaan transportasi yang beroperasi disuatu daerah, maka akan semakin tinggi pula potensi pencemaran udara di daerah tersebut. Jika pembakaran pada kendaraan bermotor tidak sempurna maka dapat dihasilkan senyawa yang berbahaya yaitu benzene (C6H6), toluene (C7H8), ethylbenzene (C8H9), dan xylene (C8H10) atau biasa disingkat BTEX. Tujuan penelitian ini adalah untuk mengidentifikasi senyawa BTEX dan senyawa hidrokarbon lainnya dalam asap kendaraan bermotor dengan menggunakan kromatografi gas-spektrometer massa (GC-MS). Hasil identifikasi menunjukkan adanya hubungan yangsangat kuat antara standard dengan hasil pengukuran yaitu dengan R2 di atas 0,99. Identifikasi menunjukkan senyawa BTEX yang terbentuk adalah Benzene, Toluene, Etil Benzene, Xylene.Kata kunci: kendaraan bermotor, hidro karbon, BTEX, GC-MS.AbstractThe use of two wheels motorized vehicles or motorcycles in Indonesia is growing rapidly. It has been known that the greater the number of two wheels motorized vehicles the higher the potential for air pollution. If the combustion occur incomplete, hazardous compounds can be generated, namely benzene (C6H6), toluene (C7H8), ethylbenzene (C8H9), and xylene (C8H10) or commonly abbreviated BTEX. The purpose of this study was to identify BTEX compounds and other hydrocarbon compounds in motor vehicle fumes using gas chromatography-mass spectrometers. The identification results indicate a very strong relationship between the standard and the measurement results, with R2 above 0.99. Identification shows that BTEX compounds formed are Benzene, Toluene, Ethyl Benzene, Xylene. Keywords: motorcycles, hidro karbon, BTEX, GC-MS.

Analysis of Aromatic Amines in Industrial Wastewater by Capillary Gas Chromatography-Mass Spectrometry

2000 ◽  
Vol 35 (2) ◽  
pp. 245-262 ◽  
Author(s):  
Francis I. Onuska ◽  
Ken A. Terry ◽  
R. James Maguire
Keyword(s):  
Gas Chromatography ◽  
Aromatic Amines ◽  
Methylene Chloride ◽  
Solid Phase ◽  
Stationary Phases ◽  
Gas Chromatography Mass Spectrometry ◽  
Substituted Anilines ◽  
Environmental Media ◽  
Solid Phase Extraction Cartridge ◽  
Wide Range

Abstract The analysis of aromatic amines, particularly benzidines, at trace levels in environmental media has been difficult because of the lack of suitable deactivated capillary column stationary phases for gas chromatography. This report describes the use of an improved type of column as well as a method for the analysis of anilines and benzidines in water, wastewater and sewage samples. Extraction procedures are applicable to a wide range of compounds that are effectively partitioned from an aqueous matrix into methylene chloride, or onto a solid-phase extraction cartridge. The extracted analytes are also amenable to separation on a capillary gas chromatographic column and transferable to the mass spectrometer. These contaminants are converted to their N-trifluoroacetyl derivatives. Aniline and some substituted anilines, and 3,3’-dichlorobenzidine and benzidine were determined in 24-h composite industrial water, wastewater, primary sludge and final effluent samples at concentrations from 0.03 up to 2760 µg/L.

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