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Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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biocompatible Solid Phase microextraction coatings based on polyacrylonitrile and Solid Phase extraction Phases
Analytical Chemistry, 2007Co-Authors: Mihaela L Musteata, And Florin Marcel Musteata, Janusz PawliszynAbstract:The applications of Solid-Phase microextraction (SPME) are continuously expanding, and one of the most interesting current aspects consists of applying SPME for fast analysis of biological fluids. The goal of this study is to develop biocompatible SPME coatings that can be utilized for in vivo and in vitro extractions, in direct contact with a biological matrix such as blood or tissue. The biocompatibility of the proposed new coatings is confirmed by X-ray photoelectron spectroscopy, and their performance is tested by developing an SPME/HPLC method for analysis of verapamil, loperamide, diazepam, nordiazepam, and warfarin in buffer solutions and in human plasma. The coatings prove to be biocompatible by not adsorbing proteins and are successfully applied for fast drug analysis and assay of drug plasma protein binding.
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Solid Phase microextraction.
Advances in experimental medicine and biology, 2001Co-Authors: Janusz PawliszynAbstract:Solid Phase Microextraction (SPME) uses a small volume of sorbent dispersed typically on the surface of small fibres, to isolate and concentrate analytes from sample matrix. After contact with sample, analytes are absorbed or adsorbed by the fibre Phase (depending on the nature of the coating) until an equilibrium is reached in the system. The amount of an analyte extracted by the coating at equilibrium is determined by the magnitude of the partition coefficient of the analyte between the sample matrix and the coating material. After the extraction step, the fibres are transferred, with the help of a syringe-like handling device, to analytical instrument, for separation and quantitation of target analytes. This technique integrates sampling, extraction and sample introduction and is a simple way of facilitating on-site monitoring. Applications of this technique include environmental monitoring, industrial hygiene, process monitoring, clinical, forensic, food, flavour, fragrance and drug analyses, in laboratory and on-site analysis.
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Solid Phase microextraction : theory and practice
1997Co-Authors: Janusz PawliszynAbstract:Solid Phase Microextraction: Theory and Practice Janusz Pawliszyn Solid Phase microextraction (SPME) is a recently proposed solvent-free sampling and sample preparation technique. SPME represents a quick, sensitive, and economical approach that can be adopted for field work and can be easily integrated with present analytical instrumentation into an automation process. Written by the inventor of the technique, Solid Phase Microextraction: Theory and Practice describes the theoretical and practical aspects of this new technology, which received an "RD* Experiments for beginners;* A summary of the practical applications of SPME in environmental, food, pharmaceutical, and forensic settings;* Material suitable for SPME courses or self-guided study.
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Headspace Solid-Phase microextraction
Analytical Chemistry, 1993Co-Authors: Zhouyao Zhang, Janusz PawliszynAbstract:Headspace Solid-Phase microextraction is a solvent-free sample preparation technique in which a fused silica fiber coated with polymeric organic liquid is introduced into the headspace above the sample. The volatilized organic analytes are extracted and concentrated in the coating and then transferred to the analytical instrument for desorption and analysis. This modification of the Solid-Phase microextraction method (SPME) shortens the time of extraction and facilitates the application of this method to analysis of Solid samples. The detection limits of the headspace SPME technique are at ppt level when ion trap mass spectrometry is used as the detector and are very similar to that of the direct SPME technique
Georg Terstappen - One of the best experts on this subject based on the ideXlab platform.
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Solid Phase solution Phase combinatorial synthesis of neuroimmunophilin ligands
Bioorganic & Medicinal Chemistry Letters, 2000Co-Authors: Michael H Rabinowitz, Pierfausto Seneci, T Rossi, Michele Dal Cin, Martyn Deal, Georg TerstappenAbstract:A novel Solid-Phase/solution-Phase strategy for the synthesis of neuroimmunophilin ligands based on GPI 1046 was developed. The synthesis employs a Solid-Phase esterification strategy followed by a solution-Phase pyruvic amide formation to produce multi-milligram quantities of discrete compounds for assay. The protocol was applied to a production library of 880 discrete compounds. A highlight of the strategy is an aqueous extractive purification of the final compounds using a novel liquid/ice extraction system developed for high throughput.
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Solid-Phase/solution-Phase combinatorial synthesis of neuroimmunophilin ligands
'Elsevier BV', 2000Co-Authors: M. Rabinowitz, Pierfausto Seneci, T Rossi, Martyn Deal, Dal M. Cin, Georg TerstappenAbstract:A novel Solid-Phase/solution-Phase strategy for the synthesis of neuroimmunophilin ligands based on GPI 1046 was developed. The synthesis employs a Solid-Phase esterification strategy followed by a solution-Phase pyruvic amide formation to produce multi-milligram quantities of discrete compounds for assay. The protocol was applied to a production library of 880 discrete compounds. A highlight of the strategy is an aqueous extractive purification of the final compounds using a novel liquid/ice extraction system developed for high throughpu
Venkat R Subramanian - One of the best experts on this subject based on the ideXlab platform.
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Efficient reformulation of Solid-Phase diffusion in physics-based lithium-ion battery models
2020Co-Authors: Venkatasailanathan Ramadesigan, Vijayasekaran Boovaragavan, Carl J Pirkle, Venkat R SubramanianAbstract:Lithium-ion batteries are typically modeled using porous electrode theory coupled with various transport and reaction mechanisms with an appropriate discretization or approximation for the Solid Phase. One of the major difficulties in simulating Li-ion battery models is the need for simulating Solid-Phase diffusion in a second dimension r. It increases the complexity of the model as well as the computation time/cost to a great extent. Traditional approach toward Solid-Phase diffusion leads to more difficulties, with the use of emerging cathode materials, which involve Phase changes and thus moving boundaries. A computationally efficient representation for Solid-Phase diffusion is discussed in this paper. The operating condition has a significant effect on the validity, accuracy, and efficiency of various approximations for the Solid-Phase diffusion. This paper compares approaches available today for Solid-Phase reformulation and provides two efficient forms for constant and varying diffusivities in the Solid Phase. This paper introduces an efficient method of an eigenfunction based Galerkin collocation and a mixed order finite difference method for approximating/representing Solid-Phase concentration variations within the active materials of porous electrodes for a pseudo-twodimensional model for lithium-ion batteries. © 2010 The Electrochemical Society. ͓DOI: 10.1149/1.3425622͔ All rights reserved. Electrochemical power sources are expected to play a vital role in the future in automobiles, power storage, military, mobile, and space applications. Lithium-ion chemistry has been identified as a good candidate for high power/high energy secondary batteries. Significant progress has been made toward modeling and understanding of lithium-ion batteries using physics-based first-principles models. First-principles-based battery models typically solve electrolyte concentration, electrolyte potential, Solid-state potential, and Solid-state concentration in the porous electrodes 1,2 and electrolyte concentration and electrolyte potential in the separator. These models are based on transport phenomena, electrochemistry, and thermodynamics. These models are represented by coupled nonlinear partial differential equations ͑PDEs͒ in one to two dimensions and are typically solved numerically and require a few minutes to hours to simulate. Even when one-dimensional transport in the macroscale ͑x͒ is considered, the continuum models that are used to describe the electrochemical behavior of lithium-ion batteries, involve three coupled nonlinear PDEs ͑in x,t͒ in each porous electrode and two coupled nonlinear PDEs ͑in x,t͒ in the separator. For predicting the thermal behavior, one has to add an additional equation for temperature. In addition, Solid-state diffusion should be solved in the pseudo second dimension ͑r͒ in the electrode. Li-ions diffuse ͑intercalate͒ into and out of the Solid particles of porous electrodes in the pseudo second dimension. Hence, in addition to the equations in the x direction, Solid-state diffusion should be solved in the pseudo dimension ͑r͒ in the porous electrodes. This diffusion in the microscale is typically modeled using Fick's law of diffusion. One of the major difficulties in the electrochemical engineering models is the inclusion of SolidPhase diffusion in a second dimension r, which increases the complexity of the model as well as the computation time/cost to a great extent. Traditional simulation approaches toward Solid-Phase diffusion lead to more difficulties with the use of emerging cathode materials, which involve Phase changes and thus moving boundaries. Concentration variations in the Solid Phase is governed by Fick's law of diffusion, and the same in spherical coordinates is given as where D s = D 0 f͑c͒. Equation 1 can be converted to a dimensionless form using the following dimensionless variables and parameters with the boundary conditions This paper discusses two computationally efficient representations for the Solid-Phase diffusion. An efficient eigenfunction based Galerkin collocation method is introduced and discussed in the paper. Further, a mixed order finite difference ͑FD͒ method with optimal node spacing is introduced, which can be used to reduce the computational cost/time significantly even with varying diffusivities in the Solid Phase. The operating condition has a significant effect on the validity, accuracy, and efficiency of various approximations for the Solid-Phase diffusion. The discretization and solver scheme used in time is also a significant factor in deciding the best possible approximation for the Solid Phase
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efficient reformulation of Solid Phase diffusion in physics based lithium ion battery models
Journal of The Electrochemical Society, 2010Co-Authors: Venkatasailanathan Ramadesigan, Vijayasekaran Boovaragavan, Carl J Pirkle, Venkat R SubramanianAbstract:Lithium-ion batteries are typically modeled using porous electrode theory coupled with various transport and reaction mechanisms with an appropriate discretization or approximation for the Solid Phase. One of the major difficulties in simulating Li-ion battery models is the need for simulating Solid-Phase diffusion in a second dimension r. It increases the complexity of the model as well as the computation time/cost to a great extent. Traditional approach toward Solid-Phase diffusion leads to more difficulties, with the use of emerging cathode materials, which involve Phase changes and thus moving boundaries. A computationally efficient representation for Solid-Phase diffusion is discussed in this paper. The operating condition has a significant effect on the validity, accuracy, and efficiency of various approximations for the Solid-Phase diffusion. This paper compares approaches available today for Solid-Phase reformulation and provides two efficient forms for constant and varying diffusivities in the Solid Phase. This paper introduces an efficient method of an eigenfunction based Galerkin collocation and a mixed order finite difference method for approximating/representing Solid-Phase concentration variations within the active materials of porous electrodes for a pseudo-two-dimensional model for lithium-ion batteries.
Steven A. Barker - One of the best experts on this subject based on the ideXlab platform.
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matrix Solid Phase dispersion mspd
ChemInform, 2007Co-Authors: Steven A. BarkerAbstract:A review of the many uses of matrix Solid Phase dispersion (MSPD) in the extraction and analysis of a variety of compounds from a range of samples is provided. Matrix Solid Phase dispersion (MSPD) has found particular application as a somewhat generic analytical process for the preparation, extraction and fractionation of Solid, semi-Solid and/or highly viscous biological samples. Its simplicity and flexibility contribute to it being chosen over more classical methods for these purposes. MSPD is based on several simple principles of chemistry and physics, involving forces applied to the sample by mechanical blending to produce complete sample disruption and the interactions of the sample matrix with a Solid support bonded-Phase (SPE) or the surface chemistry of other Solid support materials. These principles are discussed as are the factors to be considered in conducting a MSPD extraction.
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matrix Solid Phase dispersion
Journal of Chromatography A, 2000Co-Authors: Steven A. BarkerAbstract:Matrix Solid-Phase dispersion (MSPD) is a patented process, first reported in 1989, for conducting simultaneous disruption and extraction of Solid and semi-Solid samples. MSPD permits complete fractionation of the sample matrix components as well as the ability to selectively elute a single compound or several classes of compounds from the same sample. The method has been applied to the isolation of drugs in food animal tissues but has also found wide application in the analysis of herbicides, pesticides and pollutants from animal tissues, fruits, vegetables and other matrices. The present article provides a review of MSPD applications in these and related fields and discusses the factors known to affect MSPD methods. Both the practical and theoretical aspects of MSPD are also presented.
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Matrix Solid-Phase dispersion
1998Co-Authors: Steven A. BarkerAbstract:Matrix Solid-Phase dispersion is an analytical technique for the preparation and extraction of Solid and viscous samples. The technique uses bonded-Phase Solid supports as an abrasive to produce disruption of sample architecture and a bound solvent to aid complete sample disruption during the sample blending process. The sample disperses over the surface of the bonded Phase-support material to provide a new mixed Phase for isolating analytes from various sample matrices. This review discusses the factors that affect the use of matrix Solid-Phase dispersion and provides a bibliography of its applications for the extraction and analysis of a range of compounds
Wilmchristian Haase - One of the best experts on this subject based on the ideXlab platform.
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Solid Phase oligosaccharide synthesis and combinatorial carbohydrate libraries
Chemical Reviews, 2000Co-Authors: Peter H. Seeberger, Wilmchristian HaaseAbstract:Preface. Contributors. Solid--Phase Carbohydrate Synthesis: The Early Work (W.--C. Haase & P. Seeberger). The Glycal Assembly Method on Solid Supports: Synthesis of Oligosaccharides and Glycoconjugates (P. Cirillo & S. Danishefsky). The Sulfoxide Glycosylation Method and its Application to Solid--Phase Oligosaccharide Synthesis and the Generation of Combinatorial Libraries (C. Taylor). The Use of O--Glycosyl Trichloroacetimidates for the Polymer--Supported Synthesis of Oligosaccharides (L. Knerr & R. Schmidt). Synthesis of Oligosaccharides on Solid Support Using Thioglycosides and Pentenyl Glycosides (V. Wittmann). Solid--Phase Oligosaccharide Synthesis Using Glycosyl Phosphates (W.--C. Haase, et al.). Stereoselective beta--Mannosylation on Polymer Support (Y. Ito & H. Ando). Tools for "On--Bead" Monitoring and Analysis in Solid--Phase Oligosaccharide Synthesis (W.--C. Haase, et al.). Polyethyleneglycol omega--Monomethylether (MPEG)--Supported Solution--Phase Synthesis of Oligosaccharides (J. Krepinsky & S. Douglas). Two--Direction Glycosylations for the Preparation of Libraries of Oligosaccharides (G.--J. Boons & T. Zhu). Carbohydrate Libraries in Solution Using Thioglycosides: From Multistep Synthesis to Programmable, One--Pot Synthesis (E. Simanek & C.--H. Wong). Carbohydrate Libraries by the Random Glycosylation Approach (O. Kanie & O. Hindsgaul). Solid--Phase Synthesis of Biologically Important Glycopeptides (N. Bezay & H. Kunz). Preparation and Screening of Glycopeptide Libraries (P. St. Hilaire, et al.). Index.
