Degradation of pentachlorophenol as a model hazardous and recalcitrant organochlorinated pollutant using AgIII

2017 ◽  
Vol 14 (8) ◽  
pp. 476 ◽  
Author(s):  
Ileana R. Zamora-Garcia ◽  
Alejandro Alatorre-Ordaz ◽  
Jorge G. Ibanez ◽  
Julio Cesar Torres-Elguera ◽  
Kazimierz Wrobel ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Ring Opening ◽  
Environmental Remediation ◽  
High Performance ◽  
Electron Capture Detection ◽  
Mass Spectrometry Detection ◽  
Halogenated Compound ◽  
Potential Applications ◽  
Uv Visible ◽  
Flame Ionisation

Environmental context Electrochemistry offers potential applications for environmental remediation. Pentachlorophenol, a highly toxic and recalcitrant halogenated compound, is degraded by a novel oxidant produced electrochemically, and the intermediates and products of the degradation are investigated. Cyclic remediation systems merit further study. Abstract The use of electrochemically generated Ag(OH)4− as a strong oxidising agent was evaluated for the treatment of a model hazardous and recalcitrant organochlorinated pollutant, pentachlorophenol (PCP). High-performance liquid chromatography (HPLC), gas chromatography with flame ionisation detection (GC-FID) or with electron capture detection (GC-ECD), gas chromatography with mass spectrometry detection and UV-visible spectroscopy were utilised to investigate intermediates and products generated during such treatment. From these, it was deduced that dechlorination occurred first, followed by an oxidative ring opening at the C=C bond that destabilised the remaining structure and generated tetrachloro-p-benzoquinone, 2,3,5,6-tetrachlorophenol, 2,3,4,6-tetrachlorophenol, 2,4,6-trichlorophenol (or 2,3,5-trichlorophenol), 2,4,5-trichlorophenol (or 2,3,6-trichlorophenol) and 2,4-dichlorophenol (or 3,4-dichlorophenol). In contrast to other remediation methods (e.g. incineration) no highly toxic molecules such as dioxins were generated by this novel degradation system.

scholarly journals Effect oF β-Alanine on The Preparation of 4-Ethoxy-Cinnamic Acid

2018 ◽  
Vol 12 (1) ◽  
pp. 58-67
Author(s):  
N. T. Hoai ◽  
Tran Thi Yen Ngoc ◽  
Nguyen Dang Nam ◽  
Tran Thu Thuy ◽  
Cao Thi Thu Trang ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Raman Spectroscopy ◽  
High Performance Liquid Chromatography ◽  
Cinnamic Acid ◽  
High Performance ◽  
Corrosion Inhibitors ◽  
Building Blocks ◽  
High Efficient ◽  
Potential Applications ◽  
Gas Chromatography Mass Spectroscopy

Objective:Cinnamic acid and its derivatives have a numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors.Method:It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming of 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid.Result:The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.Cinnamic acid and its derivatives have numerous potential applications in many different fields such as pharmacy, organic “building blocks”, and corrosion inhibitors. It is well-known that Verley-Doebner modification is a high efficient method for the preparation of cinnamic acid derivaties, especially with the compounds containing electron-donating subtituents at para position in aromatic ring. In this paper, 4-ethoxy-cinnamic acid was synthesized according to Verley-Doebner reaction with the use of pyrine acting as catalyst and solvent. The effect of the β-alanine concentration on the conversion of the starting material of 4-ethoxy-benzaldehyde was thoroughly investigated using high performance liquid chromatography. The results showed that consuming 8% of β-alanine would convert 100% of 4-ethoxy-benzaldehyde to 4-ethoxy-cinnamic acid. The structure of the obtained 4-ethoxy-cinnamic acid was also confirmed using Fourier transform infrared spectroscopy, Raman spectroscopy, and Gas chromatography-Mass spectroscopy.

scholarly journals The role of volatile organic compounds in the polluted urban atmosphere of Bristol, England

2003 ◽  
Vol 3 (4) ◽  
pp. 1165-1176 ◽  
Author(s):  
A. C. Rivett ◽  
D. Martin ◽  
D. J. Gray ◽  
C. S. Price ◽  
G. Nickless ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Late Summer ◽  
Early Spring ◽  
Urban Atmosphere ◽  
Electron Capture Detection ◽  
Night Time ◽  
Urban Background ◽  
Flame Ionisation ◽  
Selection Of

Abstract. The results of a field campaign carried out from early spring through to the late summer of 2000, in Bristol, England, are presented. Continuous measurements of over 40 hydrocarbons have been made at an urban background site, located at Bristol University, for approximately nine months using a Gas Chromatography - Flame Ionisation Detection (GC-FID) system and for a selection of halocarbons for approximately one month using a Gas Chromatography - Electron Capture Detection (GC-ECD) system. In this paper we present the time-series of the nine halocarbons and selected hydrocarbons. Daytime and night-time hydroxyl radical concentrations have been estimated based on the diurnal variations of a selection of the measured hydrocarbons. The average summer daytime concentration of OH was found to be 2.5x106 molecules cm-3 and the night-time concentration to be in the range 104 to 105 molecules cm-3. In addition, the role played by certain VOCs in the formation of ozone is assessed using the POCP (Photochemical Ozone Creation Potential) concept.

Degradation products of proguanil — 4-chloroaniline and related components with regard to genotoxicity

2013 ◽  
Vol 67 (6) ◽  
Author(s):  
Katharina Schulz ◽  
Ulrich Oberdieck ◽  
Werner Weitschies
Keyword(s):  
Gas Chromatography ◽  
High Performance ◽  
Degradation Products ◽  
Database Analysis ◽  
Toxicological Evaluation ◽  
Drug Products ◽  
Chemical Structures ◽  
Genotoxic Impurities ◽  
Main Degradation Product ◽  
Flame Ionisation

AbstractIn the event of genotoxic impurities in drug products, knowledge of the origin and fate of these components is of particular importance. In the present study, commercially available proguanil tablets (Paludrine®) were investigated in respect of formation of the main degradation product, 4-chloroaniline (PCA), which is known to be genotoxic. The investigations made use of high performance liquid chromatography coupled with fluorescence detection (HPLC-FLD) and gas chromatography coupled with flame ionisation detection (GC-FID) systems. In addition, proposals for the structure of further proguanil degradation products were developed based on results obtained by mass spectroscopy (HPLC-MS). Database analysis using DEREK, MCASE, and Vitic was performed to obtain an initial toxicological evaluation of the proposed chemical structures. Finally, the absence of the newly established structures in stored proguanil tablets was verified.

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