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U Narkiewicz - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of carbon dioxide on TEPA-modified TiO2/titanate composite nanorods
New Journal of Chemistry, 2020Co-Authors: Joanna Kapica-kozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Jaroslaw Serafin, Antoni W Morawski, Ewelina Kusiak-nejman, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
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adsorption of carbon dioxide on TEPA modified tio2 titanate composite nanorods
New Journal of Chemistry, 2017Co-Authors: Joanna Kapicakozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Ewelina Kusiaknejman, Jaroslaw Serafin, Antoni W Morawski, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
Jos H Beijnen - One of the best experts on this subject based on the ideXlab platform.
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polymorphisms of drug metabolizing enzymes gst cyp2b6 and cyp3a affect the pharmacokinetics of thioTEPA and TEPA
British Journal of Clinical Pharmacology, 2009Co-Authors: Corine Ekhart, S Rodenhuis, Jos H Beijnen, Valerie D Doodeman, Paul H M Smits, Alwin D R HuitemaAbstract:AIMS ThioTEPA is widely used in high-dose chemotherapy. Previous studies have shown relations between exposure and severe organ toxicity. ThioTEPA is metabolized by cytochrome P450 and glutathione S-transferase enzymes. Polymorphisms of these enzymes may affect elimination of thioTEPA and TEPA, its main metabolite. The purpose of this study was to evaluate effects of known allelic variants in CYP2B6, CYP3A4, CYP3A5, GSTA1 and GSTP1 genes on pharmacokinetics of thioTEPA and TEPA.
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population pharmacokinetics of thioTEPA and its active metabolite TEPA in patients undergoing high dose chemotherapy
British Journal of Clinical Pharmacology, 2008Co-Authors: Alwin D R Huitema, Ron A A Mathot, M M Tibben, Jan H M Schellens, S Rodenhuis, Jos H BeijnenAbstract:Aims To study the population pharmacokinetics of thioTEPA and its main metabolite TEPA in patients receiving high-dose chemotherapy consisting of thioTEPA (80–120 mg m−2 day−1), cyclophosphamide (1000–1500 mg m−2 day−1) and carboplatin (265–400 mg m−2 day−1) for 4 days. Methods ThioTEPA and TEPA kinetic data were processed with a two-compartment model using the nonlinear mixed effect modelling program NONMEM. Interindividual variability (IIV), interoccasion variability (IOV) and residual variability in the pharmacokinetics were estimated. The influence of patient characteristics on the pharmacokinetics was also determined. Results A total number of 40 patients receiving 65 courses of chemotherapy was included. Clearance of thioTEPA (CL) was 34 l h−1 with an IIV and IOV of 18 and 11%, respectively. The volume of distribution of thioTEPA was 47 l (IIV = 7.5%; IOV = 19%). The fraction of thioTEPA converted to TEPA divided by the volume of distribution of TEPA was 0.030 l−1 (IIV = 39%; IOV = 32%) and the elimination rate constant of TEPA was 0.64 h−1 (IIV = 27%; IOV = 32%). CL of thioTEPA was correlated with alkaline phosphatase and serum albumin. The volume of distribution of thioTEPA and the elimination rate constant of TEPA were correlated with total protein levels and body weight, respectively. Conclusions A model for the description of the pharmacokinetics of thioTEPA and TEPA was developed. Factors involved in the interpatient variability of thioTEPA and TEPA pharmacokinetics were identified. Since, IOV of both thioTEPA and TEPA was equal to or smaller than IIV, therapeutic drug monitoring based on data of previous courses may be meaningful using this population model.
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simultaneous determination of thioTEPA TEPA and a novel recently identified thioTEPA metabolite monochloroTEPA in urine using capillary gas chromatography
Journal of Chromatography B: Biomedical Sciences and Applications, 2000Co-Authors: Jos H Beijnen, M J Van Maanen, Doesburg K SmitsAbstract:An assay for the simultaneous quantitative determination of thioTEPA, TEPA and the recently identified metabolite N,N′-diethylene-N″-2-chloroethylphosphoramide (monochloroTEPA) in human urine has been developed. MonochloroTEPA was synthesized by incubation of TEPA with sodium chloride at pH 8. Thus, with this assay monochloroTEPA is quantified as TEPA equivalents. Analysis of the three analytes in urine was performed using gas chromatography with selective nitrogen–phosphorous detection after extraction with a mixture of 1-propanol and chloroform from urine samples. Diphenylamine was used as internal standard. Recoveries ranged between 70 and 100% and both accuracy and precision were less than 15%. Linearity was accomplished in the range of 25–2500 ng/ml for monochloroTEPA and 25–5000 ng/ml for thioTEPA and TEPA. MonochloroTEPA proved to be stable in urine for at least 4 weeks at −80°C. ThioTEPA, TEPA and monochloroTEPA cummulative urinary excretion from two patients treated with thioTEPA are presented demonstrating the applicability of the assay for clinical samples and that the excreted amount of monochloroTEPA exceeded that of thioTEPA on day 2 to 5 of urine collection.
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stability of thioTEPA and its metabolites TEPA monochloroTEPA and thioTEPA mercapturate in plasma and urine
International Journal of Pharmaceutics, 2000Co-Authors: Jos H Beijnen, Maria J Van Maanen, Karen Doesburg Smits, Mirjam J A Damen, Albert J R HeckAbstract:Abstract The degradation of N,N′,N′′ -triethylenethiophosphoramide (thioTEPA) and its metabolites N,N′,N′′ -triethylenephosphoramide (TEPA), N,N′ -diethylene, N′′ -2-chloroethylphosphoramide (monochloroTEPA) and thioTEPA-mercapturate in plasma and urine has been investigated. ThioTEPA, TEPA and monochloroTEPA were analyzed using a gas chromatographic (GC) system with selective nitrogen/phosphorous detection; thioTEPA-mercapturate was analyzed on a liquid chromatography-mass spectrometric (LC-MS) system. The influences of pH and temperature on the stability of thioTEPA and its metabolites were studied. An increase in degradation rate was observed with decreasing pH as measured for all studied metabolites. In urine the rate of degradation at 37°C was approximately 2.5±1 times higher than at 22°C. At 37°C thioTEPA and TEPA were more stable in plasma than in urine, with half lives ranging from 9–20 h for urine and 13–34 h for plasma at pH 6. Mono- and dichloro derivatives of thioTEPA were formed in urine and the monochloro derivative was found in plasma. Degradation of TEPA in plasma and urine resulted in the formation of monochloroTEPA. During the degradation of TEPA in plasma also the methoxy derivative of TEPA was formed as a consequence of the applied procedure. The monochloro derivative of thioTEPA-mercapturate was formed in urine, whereas for monochloroTEPA no degradation products could be detected.
Joanna Kapicakozar - One of the best experts on this subject based on the ideXlab platform.
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adsorption of carbon dioxide on TEPA modified tio2 titanate composite nanorods
New Journal of Chemistry, 2017Co-Authors: Joanna Kapicakozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Ewelina Kusiaknejman, Jaroslaw Serafin, Antoni W Morawski, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
Antoni W Morawski - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of carbon dioxide on TEPA-modified TiO2/titanate composite nanorods
New Journal of Chemistry, 2020Co-Authors: Joanna Kapica-kozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Jaroslaw Serafin, Antoni W Morawski, Ewelina Kusiak-nejman, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
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adsorption of carbon dioxide on TEPA modified tio2 titanate composite nanorods
New Journal of Chemistry, 2017Co-Authors: Joanna Kapicakozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Ewelina Kusiaknejman, Jaroslaw Serafin, Antoni W Morawski, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
Jaroslaw Serafin - One of the best experts on this subject based on the ideXlab platform.
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Adsorption of carbon dioxide on TEPA-modified TiO2/titanate composite nanorods
New Journal of Chemistry, 2020Co-Authors: Joanna Kapica-kozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Jaroslaw Serafin, Antoni W Morawski, Ewelina Kusiak-nejman, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
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adsorption of carbon dioxide on TEPA modified tio2 titanate composite nanorods
New Journal of Chemistry, 2017Co-Authors: Joanna Kapicakozar, Beata Michalkiewicz, Rafal J Wrobel, Sylwia Mozia, Ewa Pirog, Ewelina Kusiaknejman, Jaroslaw Serafin, Antoni W Morawski, U NarkiewiczAbstract:A titanate–TiO2 composite was obtained through hydrothermal treatment of TiO2 in KOH solution. The presence of a titanate phase was confirmed by X-ray diffraction (XRD), whereas scanning electron microscopy (SEM) measurements showed the porous nanorod structure of the material. The obtained nanorods were treated with tetraethylenepentamine (TEPA). Such synthesized sorbents were applied for CO2 removal. The CO2 capacity under a pressure of 1 bar and at 80 °C was 0.47, 0.34, and 3.11 mmol g−1 for the starting TiO2, the titanate–TiO2 composite and the TEPA–titanate–TiO2 composite (27.4 wt% of TEPA), respectively. The experimental isotherms of CO2 were analysed using the Langmuir, Freundlich, Sips, Toth, Unilan, Redlich–Peterson, Radke–Prausnitz, Dubinin–Radushkevich, Temkin and Pyzhev, and Jovanovich models. The error sums of squares (SSR) function was used to test the fit of the models. The analysis revealed that the Sips isotherm is the best-fitting model for the CO2 adsorption on the starting TiO2, whereas the Freundlich equation should be used to describe the CO2 adsorption isotherm on the titanate–TiO2 composite. The CO2 adsorption on the TEPA-modified sorbents was proposed to be described using the Sips isotherm for physical sorption and the modified Sips model for chemical sorption. The calculated isosteric heat of adsorption was found to be ≈46 kJ mol−1, which is about two times higher than the heat of CO2 absorption in liquid TEPA reported in the literature (i.e. ≈85 kJ mol−1). Therefore, it was concluded that the TEPA–titanate–TiO2 composite is an attractive alternative for liquid amines due to the lower energy of regeneration in the sorption–desorption process. The material was proved to be stable during multiple sorption–desorption cycles. Moreover, its thermal stability up to 150 °C was confirmed by thermogravimetric analysis (TGA). All these features make it a promising alternative for sorbents based on liquid amines.
