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James S Chickos - One of the best experts on this subject based on the ideXlab platform.
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vaporization enthalpy and vapor pressure of ambroxide and Galaxolide by correlation gas chromatography
The Journal of Chemical Thermodynamics, 2019Co-Authors: Kanyavee Wootitunthipong, James S ChickosAbstract:Abstract The vapor pressures and vaporization enthalpies of dibenzofuran, (−) Ambroxide™ and Galaxolide™ are evaluated by correlation gas chromatography. (−) Ambroxide™ and Galaxolide™ are important commercial products, the latter of which has been the subject of some controversy regarding its impact on the environment. All are cyclic ethers. Dibenzofuran, with established literature values was chosen to evaluate the effectiveness of using hydrocarbons to evaluate both vaporization enthalpies and liquid vapor pressures of simple ethers. Vaporization enthalpy results on dibenzofuran are consistent with the literature value. Current results suggest that hydrocarbons can also be employed to successfully evaluate both liquid vapor pressures and vaporization enthalpies at ambient temperatures for substances for this class of compounds if suitable standards are unavailable.
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Vaporization enthalpy and vapor pressure of (−) Ambroxide and Galaxolide by correlation gas chromatography
The Journal of Chemical Thermodynamics, 2019Co-Authors: Kanyavee Wootitunthipong, James S ChickosAbstract:Abstract The vapor pressures and vaporization enthalpies of dibenzofuran, (−) Ambroxide™ and Galaxolide™ are evaluated by correlation gas chromatography. (−) Ambroxide™ and Galaxolide™ are important commercial products, the latter of which has been the subject of some controversy regarding its impact on the environment. All are cyclic ethers. Dibenzofuran, with established literature values was chosen to evaluate the effectiveness of using hydrocarbons to evaluate both vaporization enthalpies and liquid vapor pressures of simple ethers. Vaporization enthalpy results on dibenzofuran are consistent with the literature value. Current results suggest that hydrocarbons can also be employed to successfully evaluate both liquid vapor pressures and vaporization enthalpies at ambient temperatures for substances for this class of compounds if suitable standards are unavailable.
Adelmo Lowe Pletsch - One of the best experts on this subject based on the ideXlab platform.
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Occurrence of pharmaceutical and personal care products (PPCPs) in marine sediments in the Todos os Santos Bay and the north coast of Salvador, Bahia, Brazil
Journal of Soils and Sediments, 2014Co-Authors: Magda Beretta, Vicky Britto, Tania Mascarenhas Tavares, Sonilda Maria Teixeira Da Silva, Adelmo Lowe PletschAbstract:Purpose The Todos os Santos Bay is the largest bay in Brazil and receives drainage from various watersheds. For more than 450 years, it was the main destination for the domestic and hospital sewage from the city of Salvador, Bahia. With the growing concern regarding the presence of pharmaceutical and personal care products (PPCPs) in the environment, an investigation was undertaken to determine the presence and levels of some commonly used drugs (i.e., atenolol, caffeine, carbamazepine, diazepam, diclofenac, erythromycin, ibuprofen) and personal care products (i.e., Galaxolide, tonalide), using sediments as an indicator of their presence in the water column. Material and methods Surficial sediment samples from 17 stations located in the intertidal zone of the Todos os Santos Bay and infralittoral zone along the north coast of Salvador were tested for the presence of some PPCPs using LC-MS/MS (for drugs) and GC-MS/MS (for fragrances). Results and discussion The PPCPs examined were present in all sediment samples at levels of parts per billion of dry sediment. The highest concentrations were found for the fragrances Galaxolide (52.5 ng g^−1) and tonalide (27.9 ng g^−1), followed by caffeine (23.4 ng g^−1) and pharmaceuticals ibuprofen (14.3 ng g^−1), atenolol (9.84 ng g^−1), carbamazepine (4.81 ng g^−1), erythromycin (2.29 ng g^−1), diclofenac (1.06 ng g^−1), and diazepam (0.71 ng g^−1). Conclusions Pharmaceuticals were found to be ubiquitous in the sediments of the study areas. The texture of the sediment was an important factor in PPCPs fixation and deposition. The concentrations of all PPCPs had statistically significant positive correlations with the percentage of clay in the sediments.
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occurrence of pharmaceutical and personal care products ppcps in marine sediments in the todos os santos bay and the north coast of salvador bahia brazil
Journal of Soils and Sediments, 2014Co-Authors: Magda Beretta, Vicky Britto, Tania Mascarenhas Tavares, Sonilda Maria Teixeira Da Silva, Adelmo Lowe PletschAbstract:The Todos os Santos Bay is the largest bay in Brazil and receives drainage from various watersheds. For more than 450 years, it was the main destination for the domestic and hospital sewage from the city of Salvador, Bahia. With the growing concern regarding the presence of pharmaceutical and personal care products (PPCPs) in the environment, an investigation was undertaken to determine the presence and levels of some commonly used drugs (i.e., atenolol, caffeine, carbamazepine, diazepam, diclofenac, erythromycin, ibuprofen) and personal care products (i.e., Galaxolide, tonalide), using sediments as an indicator of their presence in the water column. Surficial sediment samples from 17 stations located in the intertidal zone of the Todos os Santos Bay and infralittoral zone along the north coast of Salvador were tested for the presence of some PPCPs using LC-MS/MS (for drugs) and GC-MS/MS (for fragrances). The PPCPs examined were present in all sediment samples at levels of parts per billion of dry sediment. The highest concentrations were found for the fragrances Galaxolide (52.5 ng g−1) and tonalide (27.9 ng g−1), followed by caffeine (23.4 ng g−1) and pharmaceuticals ibuprofen (14.3 ng g−1), atenolol (9.84 ng g−1), carbamazepine (4.81 ng g−1), erythromycin (2.29 ng g−1), diclofenac (1.06 ng g−1), and diazepam (0.71 ng g−1). Pharmaceuticals were found to be ubiquitous in the sediments of the study areas. The texture of the sediment was an important factor in PPCPs fixation and deposition. The concentrations of all PPCPs had statistically significant positive correlations with the percentage of clay in the sediments.
Kanyavee Wootitunthipong - One of the best experts on this subject based on the ideXlab platform.
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vaporization enthalpy and vapor pressure of ambroxide and Galaxolide by correlation gas chromatography
The Journal of Chemical Thermodynamics, 2019Co-Authors: Kanyavee Wootitunthipong, James S ChickosAbstract:Abstract The vapor pressures and vaporization enthalpies of dibenzofuran, (−) Ambroxide™ and Galaxolide™ are evaluated by correlation gas chromatography. (−) Ambroxide™ and Galaxolide™ are important commercial products, the latter of which has been the subject of some controversy regarding its impact on the environment. All are cyclic ethers. Dibenzofuran, with established literature values was chosen to evaluate the effectiveness of using hydrocarbons to evaluate both vaporization enthalpies and liquid vapor pressures of simple ethers. Vaporization enthalpy results on dibenzofuran are consistent with the literature value. Current results suggest that hydrocarbons can also be employed to successfully evaluate both liquid vapor pressures and vaporization enthalpies at ambient temperatures for substances for this class of compounds if suitable standards are unavailable.
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Vaporization enthalpy and vapor pressure of (−) Ambroxide and Galaxolide by correlation gas chromatography
The Journal of Chemical Thermodynamics, 2019Co-Authors: Kanyavee Wootitunthipong, James S ChickosAbstract:Abstract The vapor pressures and vaporization enthalpies of dibenzofuran, (−) Ambroxide™ and Galaxolide™ are evaluated by correlation gas chromatography. (−) Ambroxide™ and Galaxolide™ are important commercial products, the latter of which has been the subject of some controversy regarding its impact on the environment. All are cyclic ethers. Dibenzofuran, with established literature values was chosen to evaluate the effectiveness of using hydrocarbons to evaluate both vaporization enthalpies and liquid vapor pressures of simple ethers. Vaporization enthalpy results on dibenzofuran are consistent with the literature value. Current results suggest that hydrocarbons can also be employed to successfully evaluate both liquid vapor pressures and vaporization enthalpies at ambient temperatures for substances for this class of compounds if suitable standards are unavailable.
M.f. Alpendurada - One of the best experts on this subject based on the ideXlab platform.
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new developments in the analysis of fragrances and earthy musty compounds in water by solid phase microextraction metal alloy fibre coupled with gas chromatography tandem mass spectrometry
Talanta, 2011Co-Authors: S. Machado, Edite Cunha, A. Guimaraes, Carlos Goncalves, M.f. AlpenduradaAbstract:Fragrances are widespread aquatic contaminants due to their presence in many personal care products used daily in developed countries. Levels of Galaxolide and tonalide are commonly found in surface waters, urban wastewaters and river sediments. On the other hand, earthy–musty compounds confer bad odour to drinking water at levels that challenge the analytical capabilities. The combined determination of earthy–musty compounds and fragrances in water would be a breakthrough to make the traditional organoleptic evaluation of the water quality stricter and safer for the analyst. Two approaches were attempted to improve the analytical capabilities: analyte pre-concentration with a newly developed PDMS-DVB solid-phase microextraction fibre on metal alloy core and sensitive detection by tandem mass spectrometry (MS/MS). The optimization of SPME parameters was carried out using a central composite design and desirability functions. The final optimum extraction conditions were: headspace extraction at 70 °C during 40 min adding 200 g L−1 of NaCl. The detection limits in tandem MS (0.02–20 ng L−1) were marginally lower compared to full scan except for geosmin and trichloroanisol which go down to 0.1 and 0.02 ng L−1, respectively. The analysis of different water matrices revealed that fragrances and earthy–musty compounds were absent from ground- and drinking waters. Surface waters of river Leca contained levels of Galaxolide around 250 ng L−1 in the 4 terminal sampling stations, which are downstream of WWTPs and polluted tributaries. Geosmine was ubiquitously distributed in natural waters similarly in rivers Leca and Douro at concentrations <7 ng L−1.
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New developments in the analysis of fragrances and earthy―musty compounds in water by solid-phase microextraction (metal alloy fibre) coupled with gas chromatography―(tandem) mass spectrometry
Talanta, 2011Co-Authors: S. Machado, Edite Cunha, A. Guimaraes, Carlos Goncalves, M.f. AlpenduradaAbstract:Fragrances are widespread aquatic contaminants due to their presence in many personal care products used daily in developed countries. Levels of Galaxolide and tonalide are commonly found in surface waters, urban wastewaters and river sediments. On the other hand, earthy–musty compounds confer bad odour to drinking water at levels that challenge the analytical capabilities. The combined determination of earthy–musty compounds and fragrances in water would be a breakthrough to make the traditional organoleptic evaluation of the water quality stricter and safer for the analyst. Two approaches were attempted to improve the analytical capabilities: analyte pre-concentration with a newly developed PDMS-DVB solid-phase microextraction fibre on metal alloy core and sensitive detection by tandem mass spectrometry (MS/MS). The optimization of SPME parameters was carried out using a central composite design and desirability functions. The final optimum extraction conditions were: headspace extraction at 70 °C during 40 min adding 200 g L−1 of NaCl. The detection limits in tandem MS (0.02–20 ng L−1) were marginally lower compared to full scan except for geosmin and trichloroanisol which go down to 0.1 and 0.02 ng L−1, respectively. The analysis of different water matrices revealed that fragrances and earthy–musty compounds were absent from ground- and drinking waters. Surface waters of river Leca contained levels of Galaxolide around 250 ng L−1 in the 4 terminal sampling stations, which are downstream of WWTPs and polluted tributaries. Geosmine was ubiquitously distributed in natural waters similarly in rivers Leca and Douro at concentrations
K M Peru - One of the best experts on this subject based on the ideXlab platform.
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Optimization of solid-phase microextraction for the gas chromatographic-mass spectrometric determination of synthetic musk fragrances in water samples.
Journal of Chromatography A, 2000Co-Authors: M Winkler, J V Headley, K M PeruAbstract:Abstract Described is a solid-phase microextraction–gas chromatography–mass spectrometric procedure for the determination of three polycyclic musk fragrances (Galaxolide, tonalide, celestolide) and a nitro musk fragrance (musk ketone) in natural river water. Both classes of the musk fragrances could be extracted reproducibly from water samples with a recovery in the range of 45–50% and relative standard deviation of 11–18% for fragrances at 25–260 ng/l levels. Detection limits were between 14 and 22 ng/l. To achieve this reproducibility it was necessary to use an internal standard, pentachloronitrobenzene, for all substances. Best recoveries were achieved with polydimethylsiloxane (PDMS)–divinylbenzene fibers (compared to recoveries obtained with PDMS, polyacrylate or carboxen fibers) and extraction times of 45 min at 30°C, with no need for attainment of equilibrium conditions. The latter was achieved at about 2 h. For Elbe River water, in the vicinity of Magdeburg, no matrix effects were observed. While the average levels of celestolide and musk ketone for samples investigated were below the detection limits, 14 and 22 ng/l, respectively, and for tonalide below the limit of quantification, 22 ng/l, the ambient levels of Galaxolide in the Elbe River were 117 ng/l.
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Optimization of solid-phase microextraction for the gas chromatographic-mass spectrometric determination of synthetic musk fragrances in water samples.
Journal of chromatography. A, 2000Co-Authors: M Winkler, J V Headley, K M PeruAbstract:Described is a solid-phase microextraction-gas chromatography-mass spectrometric procedure for the determination of three polycyclic musk fragrances (Galaxolide, tonalide, celestolide) and a nitro musk fragrance (musk ketone) in natural river water. Both classes of the musk fragrances could be extracted reproducibly from water samples with a recovery in the range of 45-50% and relative standard deviation of 11-18% for fragrances at 25-260 ng/l levels. Detection limits were between 14 and 22 ng/l. To achieve this reproducibility it was necessary to use an internal standard, pentachloronitrobenzene, for all substances. Best recoveries were achieved with polydimethylsiloxane (PDMS)-divinylbenzene fibers (compared to recoveries obtained with PDMS, polyacrylate or carboxen fibers) and extraction times of 45 min at 30 degrees C, with no need for attainment of equilibrium conditions. The latter was achieved at about 2 h. For Elbe River water, in the vicinity of Magdeburg, no matrix effects were observed. While the average levels of celestolide and musk ketone for samples investigated were below the detection limits, 14 and 22 ng/l, respectively, and for tonalide below the limit of quantification, 22 ng/l, the ambient levels of Galaxolide in the Elbe River were 117 ng/l.
