The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured ...The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-mass spectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs, and organic acids before Chinese Spring Festival Eve （1025.5, 95.9, and 543.3 ng/m3, respectively） were higher than those after （536.6, 58.9, and 331.8 ng/m3, respectively）, n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime because of high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n- alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal, but the combustion of gasoline was in the next place. The ratios of C18：0/C16 indicated the contribution of vehicular emissions to the fatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organic acid and the photochemical degradation of aromatic hydrocarbons was the main source.展开更多
Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical car...Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.展开更多
The degradation of the alkanolamine solvent used in the removal of acid gases from natural gas streams due to exposure to contaminants, thermal degradation and presence of oxygen or oxygen containing compounds will ch...The degradation of the alkanolamine solvent used in the removal of acid gases from natural gas streams due to exposure to contaminants, thermal degradation and presence of oxygen or oxygen containing compounds will change the solvent properties, such as heat transfer coefficient, diffusion coefficient, and mass transfer coefficient of the solvent. Therefore, characterization and quantification of amine degradation product becomes one of the important analyses to determine alkanolamine solvent’s health. In order to identify degradation products of alkanolamine solvent, analytical strategies by using mass spectrometry (MS) as detector have been studied extensively. In this work, due to the low concentration of the amine degradation product, a method was developed for identification of alkanolamine degradation products using LCMS-QTOF technique. A strategy for identification of trace degradation products has been identified. Six (6) alkanolamine degradation products had been identified by using LCMS-QTOF targeted analysis in the blended alkanolamine solvent used in natural gas processing plant. Another fifteen (15) molecular formulas having similarity in chemical structure to alkanolamine degradation products were identified using untargeted analysis strategy, as possible compounds related to degradation products. Using LCMS-QTOF via targeted and untargeted analysis strategy, without tedious column separation and reference standard, enables laboratory to provide a quick and indicative information for alkanolamine solvent’s organic degradation compounds identification in CO<sub>2</sub> adsorption, within reasonable analysis time.展开更多
Solvent-free reactions of 1, 3-cyclohexanedione, 5, 5-dimethyl-1, 3-cyclohexanedione, 2, 4-pentanedione and ethyl acetoacetate with C60 in the presence of Mn（OAc）3·2H2O and ceric ammonium nitrate （CAN） under ...Solvent-free reactions of 1, 3-cyclohexanedione, 5, 5-dimethyl-1, 3-cyclohexanedione, 2, 4-pentanedione and ethyl acetoacetate with C60 in the presence of Mn（OAc）3·2H2O and ceric ammonium nitrate （CAN） under the high-speed vibration milling conditions afforded dihydrofuran-fused C60 derivatives. CAN is the better oxidant than Mn（OAc）3·2H2O in these mechanochemical reactions.展开更多
Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Th...Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Their sequence of extraction ability for W is as follows: quarternary amine > tertiary amine > secondary amine > primary amine. Acidic organophosphorus extractants do not extract W, but can extract Mo with high extraction ability from the acidic solution. These extractants could provide a potential process for separating W from Mo.展开更多
Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic deriva...Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic derivative of dimethyl malonate in high yields in solvent-free condition. 2009 Mohammad Reza Shushizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
Phenolic compounds are naturally extracted molecules used nowadays for several industrial applications such as food preservatives and neutraciticals;thus industrial needs are in constant growth. Optimization of phenol...Phenolic compounds are naturally extracted molecules used nowadays for several industrial applications such as food preservatives and neutraciticals;thus industrial needs are in constant growth. Optimization of phenolic compounds (PC) and monomeric anthocyanins (MA) extraction from grape berries using response surface methodology was here achieved. Cabernet Sauvignon (CS) wine grapes (Vitis vinifera L. cv. Cabernet Sauvignon) are a rich source of anti-radical phe- nols, extractable as dietary supplements. However, efficiency of extraction strongly depends on specific experimental conditions. In this work, the comparison between two extraction mixtures, Acetone/Water (A/W) and Methanol/Water (M/W) and the effects of three critical variables—Extraction Time (between 8 and 88 h), Extraction Temperature (between 1?C and 35?C) and Solvent Content (between 63% and 97%)—on Phenolic Compounds Yield (PCY) and Monomeric Anthocyanins Yield (MAY) were studied using Response Surface Methodology (RSM). Process conditions maximizing the PCY were found to be 87% A/W solvent content, after 88 h incubation at 26?C, and those of the MAY were found to be 97% M/W solvent content, after 8 h incubation at 1?C. In addition, chromatographic profiles of extracts showed very different affinities of the phenolic compounds families to the experimental conditions employed. This process advantages are: low percentage of organic solvent used, high quality of extracted molecules thanks to low temperature treatment, very low energy consumption and low cost of needed machinery. At industrial scale, it may be used as promising technique for the extraction of bioactive compounds from plant or byproduct material such as from wine or grape juice industries.展开更多
Twelve Australian grown faba bean genotypes with seed colour ranging from white, different shades of buff/beige, green, red and purple, were extracted using 80% methanol (v/v) or 70% acetone (v/v). The findings showed...Twelve Australian grown faba bean genotypes with seed colour ranging from white, different shades of buff/beige, green, red and purple, were extracted using 80% methanol (v/v) or 70% acetone (v/v). The findings showed that commonly consumed buff-coloured genotypes have comparable phenolic contents and antioxidant activities to those with exotic seed coat colour (red, green and purple). In general, the extraction yield for methanol and acetone extracts of faba bean genotypes were similar. However, the acetone extracts of faba bean varieties with coloured seed coats exhibited higher antioxidant activities than their methanol extracts counterparts. Phenolic compounds and antioxidant activities of the genotypes were compared in an array of chemical-based assays and profiled using an on-line high-performance liquid chromatography-post column derivatization (HPLC-PCD) system. The total phenolic content (TPC) and total flavonoid content (TFC) of acetone extracts were approximately twice those of methanol extracts. The acetone extracts contained six times higher levels of di(phenyl)-(2,4,6-trinitrophenyl) imi- noazanium radical scavenging activity (DPPH), six times higher Total Equivalent Antioxidant Capacity (TEAC) and two times higher Ferric Reducing Antioxidant Power (FRAP) than those of methanol extracts. In general, the methanol extracts of white-coloured faba bean genotype exhibited comparable phenolic contents and antioxidant activities to varieties with coloured seed coats. However, the TPC, TFC, DPPH, TEAC and FRAP of acetone extracts from white-coloured genotype were 2 - 4, 1 - 2, 5 - 9, 2 - 3 and 1 - 2 times lower than those of faba bean varieties with coloured seed coats. HPLC-PCD analyses showed substantial antioxidant responses, represented as a dense “hump” of peaks in the HPLC chromatograms of acetone extracts from coloured-genotypes. This “hump” was not detected in the chromatograms of white-genotype acetone extracts, or in chromatograms of methanol extracts regardless of genotype or seed coat colour. All coloured-beans had higher phenolic contents and antioxidant activities than the white-genotype. Hydroxybenzoic acids/flavanols, hydroxycinnamic acids and flavonols were dominant in coloured beans. The findings suggest potentials in selecting commonly consumed buff-coloured faba bean genotypes within the breeding programs for enhanced levels of phenolic compounds and antioxidant activities, potentially increasing their health-promoting properties. And, there might also be potentials in developing faba bean extracts for pharmaceutical or natural medicines.展开更多
Ten spices marketed in Jordan, (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L.,Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculu...Ten spices marketed in Jordan, (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L.,Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum vulgare Mill and Laurus nobilis L.) were investigated for their phenolic compounds and antioxidant activity. The influence of different extractants (methanol, ethanol and acetone) at different temperatures (20, 40 and 60°C) was examined. Results showed at 60°C using methanol, cloves had the highest level of total phenolics (781.0 mg GAE/100g using acetone). At 40°C, sumac and cloves had the highest amounts of total phenolics (343.9 mg/100g and 342 mg GAE/100g respectively). At 20°C, cloves continued to have the highest amount of total phenolics (394.7 mg/100g) using methanol as extactant. Ethanol as extractant, cloves gave the highest level of phenolics (548 mg GAE/100g, 493.4 mg GAE/100g) at 60°C, while at 20°C cloves and sumac showed the highest concentrations of phenolics (350.8 mg GAE/100g and 342.8 mg GAE/100g respectively). Acetone as extractant at 60°C, cloves had the highest levels of phenolics (781 mg GAE/100g) while at 40°C and at 20°C, sumac contributed the highest levels of total phenolics (583.2 mg GAE/100g and 754.5 mg GAE/100g). The total phenolics concentration varied significantly among the spices. Their values varied according to the extractant and extracting temperature. IC<sub>50</sub> (radical scavenging activity) reflecting the antioxidant activity was presented. Results showed that cloves had the highest antioxidant activity while the cinnamon, turmeric and sumac had a appreciable level of antioxidant activity. Green cardamom and coriander had the lowest antioxidant activity. Antioxidant activity was positively correlated with total phenolic compounds content of the investigated spices.展开更多
基金supported by the National Basic Re-search Program (973) of China (No. 2007CB407303)the National Natural Science Foundation of China (No.40525016)the Hi-Tech Research and Development Program (863) of China (No. 2006AA06A301).
文摘The solvent extractable organic compounds （SEOC）, including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, and dicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-mass spectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs, and organic acids before Chinese Spring Festival Eve （1025.5, 95.9, and 543.3 ng/m3, respectively） were higher than those after （536.6, 58.9, and 331.8 ng/m3, respectively）, n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime because of high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n- alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal, but the combustion of gasoline was in the next place. The ratios of C18：0/C16 indicated the contribution of vehicular emissions to the fatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organic acid and the photochemical degradation of aromatic hydrocarbons was the main source.
文摘Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower.
文摘The degradation of the alkanolamine solvent used in the removal of acid gases from natural gas streams due to exposure to contaminants, thermal degradation and presence of oxygen or oxygen containing compounds will change the solvent properties, such as heat transfer coefficient, diffusion coefficient, and mass transfer coefficient of the solvent. Therefore, characterization and quantification of amine degradation product becomes one of the important analyses to determine alkanolamine solvent’s health. In order to identify degradation products of alkanolamine solvent, analytical strategies by using mass spectrometry (MS) as detector have been studied extensively. In this work, due to the low concentration of the amine degradation product, a method was developed for identification of alkanolamine degradation products using LCMS-QTOF technique. A strategy for identification of trace degradation products has been identified. Six (6) alkanolamine degradation products had been identified by using LCMS-QTOF targeted analysis in the blended alkanolamine solvent used in natural gas processing plant. Another fifteen (15) molecular formulas having similarity in chemical structure to alkanolamine degradation products were identified using untargeted analysis strategy, as possible compounds related to degradation products. Using LCMS-QTOF via targeted and untargeted analysis strategy, without tedious column separation and reference standard, enables laboratory to provide a quick and indicative information for alkanolamine solvent’s organic degradation compounds identification in CO<sub>2</sub> adsorption, within reasonable analysis time.
基金We are grateful for the financial support from the National Science Fund for Distinguished Young Scholars(20125205)Anhui Provincial Bureau of Human Resources(2001Z019).
文摘Solvent-free reactions of 1, 3-cyclohexanedione, 5, 5-dimethyl-1, 3-cyclohexanedione, 2, 4-pentanedione and ethyl acetoacetate with C60 in the presence of Mn（OAc）3·2H2O and ceric ammonium nitrate （CAN） under the high-speed vibration milling conditions afforded dihydrofuran-fused C60 derivatives. CAN is the better oxidant than Mn（OAc）3·2H2O in these mechanochemical reactions.
文摘Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Their sequence of extraction ability for W is as follows: quarternary amine > tertiary amine > secondary amine > primary amine. Acidic organophosphorus extractants do not extract W, but can extract Mo with high extraction ability from the acidic solution. These extractants could provide a potential process for separating W from Mo.
基金Science and Research University for financial support of this work
文摘Activated methylene compound such as dimethyl malonate reacted readily with benzylic alcohols in the presence of ferric chloride/silica gel mixture （FeCl3/SiO2） under microwave irradiation to produce benzylic derivative of dimethyl malonate in high yields in solvent-free condition. 2009 Mohammad Reza Shushizadeh. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
文摘Phenolic compounds are naturally extracted molecules used nowadays for several industrial applications such as food preservatives and neutraciticals;thus industrial needs are in constant growth. Optimization of phenolic compounds (PC) and monomeric anthocyanins (MA) extraction from grape berries using response surface methodology was here achieved. Cabernet Sauvignon (CS) wine grapes (Vitis vinifera L. cv. Cabernet Sauvignon) are a rich source of anti-radical phe- nols, extractable as dietary supplements. However, efficiency of extraction strongly depends on specific experimental conditions. In this work, the comparison between two extraction mixtures, Acetone/Water (A/W) and Methanol/Water (M/W) and the effects of three critical variables—Extraction Time (between 8 and 88 h), Extraction Temperature (between 1?C and 35?C) and Solvent Content (between 63% and 97%)—on Phenolic Compounds Yield (PCY) and Monomeric Anthocyanins Yield (MAY) were studied using Response Surface Methodology (RSM). Process conditions maximizing the PCY were found to be 87% A/W solvent content, after 88 h incubation at 26?C, and those of the MAY were found to be 97% M/W solvent content, after 8 h incubation at 1?C. In addition, chromatographic profiles of extracts showed very different affinities of the phenolic compounds families to the experimental conditions employed. This process advantages are: low percentage of organic solvent used, high quality of extracted molecules thanks to low temperature treatment, very low energy consumption and low cost of needed machinery. At industrial scale, it may be used as promising technique for the extraction of bioactive compounds from plant or byproduct material such as from wine or grape juice industries.
文摘Twelve Australian grown faba bean genotypes with seed colour ranging from white, different shades of buff/beige, green, red and purple, were extracted using 80% methanol (v/v) or 70% acetone (v/v). The findings showed that commonly consumed buff-coloured genotypes have comparable phenolic contents and antioxidant activities to those with exotic seed coat colour (red, green and purple). In general, the extraction yield for methanol and acetone extracts of faba bean genotypes were similar. However, the acetone extracts of faba bean varieties with coloured seed coats exhibited higher antioxidant activities than their methanol extracts counterparts. Phenolic compounds and antioxidant activities of the genotypes were compared in an array of chemical-based assays and profiled using an on-line high-performance liquid chromatography-post column derivatization (HPLC-PCD) system. The total phenolic content (TPC) and total flavonoid content (TFC) of acetone extracts were approximately twice those of methanol extracts. The acetone extracts contained six times higher levels of di(phenyl)-(2,4,6-trinitrophenyl) imi- noazanium radical scavenging activity (DPPH), six times higher Total Equivalent Antioxidant Capacity (TEAC) and two times higher Ferric Reducing Antioxidant Power (FRAP) than those of methanol extracts. In general, the methanol extracts of white-coloured faba bean genotype exhibited comparable phenolic contents and antioxidant activities to varieties with coloured seed coats. However, the TPC, TFC, DPPH, TEAC and FRAP of acetone extracts from white-coloured genotype were 2 - 4, 1 - 2, 5 - 9, 2 - 3 and 1 - 2 times lower than those of faba bean varieties with coloured seed coats. HPLC-PCD analyses showed substantial antioxidant responses, represented as a dense “hump” of peaks in the HPLC chromatograms of acetone extracts from coloured-genotypes. This “hump” was not detected in the chromatograms of white-genotype acetone extracts, or in chromatograms of methanol extracts regardless of genotype or seed coat colour. All coloured-beans had higher phenolic contents and antioxidant activities than the white-genotype. Hydroxybenzoic acids/flavanols, hydroxycinnamic acids and flavonols were dominant in coloured beans. The findings suggest potentials in selecting commonly consumed buff-coloured faba bean genotypes within the breeding programs for enhanced levels of phenolic compounds and antioxidant activities, potentially increasing their health-promoting properties. And, there might also be potentials in developing faba bean extracts for pharmaceutical or natural medicines.
文摘Ten spices marketed in Jordan, (Syzygium aromaticum L., Coriadrum sativum L., Cuminum cyminum L.,Zingiber officinale Rosc., Elettaria cardamomum, Curcuma longa, Rhus coriaria L., Cinnamomum zeylanicum Blume, Foeniculum vulgare Mill and Laurus nobilis L.) were investigated for their phenolic compounds and antioxidant activity. The influence of different extractants (methanol, ethanol and acetone) at different temperatures (20, 40 and 60°C) was examined. Results showed at 60°C using methanol, cloves had the highest level of total phenolics (781.0 mg GAE/100g using acetone). At 40°C, sumac and cloves had the highest amounts of total phenolics (343.9 mg/100g and 342 mg GAE/100g respectively). At 20°C, cloves continued to have the highest amount of total phenolics (394.7 mg/100g) using methanol as extactant. Ethanol as extractant, cloves gave the highest level of phenolics (548 mg GAE/100g, 493.4 mg GAE/100g) at 60°C, while at 20°C cloves and sumac showed the highest concentrations of phenolics (350.8 mg GAE/100g and 342.8 mg GAE/100g respectively). Acetone as extractant at 60°C, cloves had the highest levels of phenolics (781 mg GAE/100g) while at 40°C and at 20°C, sumac contributed the highest levels of total phenolics (583.2 mg GAE/100g and 754.5 mg GAE/100g). The total phenolics concentration varied significantly among the spices. Their values varied according to the extractant and extracting temperature. IC<sub>50</sub> (radical scavenging activity) reflecting the antioxidant activity was presented. Results showed that cloves had the highest antioxidant activity while the cinnamon, turmeric and sumac had a appreciable level of antioxidant activity. Green cardamom and coriander had the lowest antioxidant activity. Antioxidant activity was positively correlated with total phenolic compounds content of the investigated spices.
