scholarly journals Preparation of Theophylline-Benzoic Acid Cocrystal and On-Line Monitoring of Cocrystallization Process in Solution by Raman Spectroscopy

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 329 ◽  
Author(s):  
Yaohui Huang ◽  
Ling Zhou ◽  
Wenchao Yang ◽  
Yang Li ◽  
Yongfan Yang ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Benzoic Acid ◽  
Raw Materials ◽  
Formation Rate ◽  
Transformation Process ◽  
Scanning Calorimetry ◽  
Preparation Methods ◽  
Suspension Density ◽  
Cooling Crystallization ◽  
On Line

Pure theophylline-benzoic acid cocrystal was prepared via slurry and cooling crystallization in solution to overcome the disadvantages of existing preparation methods. The target cocrystal was characterized by powder X-ray diffraction (PXRD), thermalgravimetric analysis (TGA), differential scanning calorimetry (DSC) and Raman spectroscopy. The slurry and cooling cocrystallization process in solution was monitored via on-line Raman spectroscopy. The results obtained from on-line Raman monitoring can exhibit the transformation process from raw materials (theophylline and benzoic acid) to cocrystal and show the cocrystal formation rate. Comparing each transformation process under different conditions in slurry crystallization, we found that suspension density of raw materials and temperature both have an impact on the theophylline-benzoic acid cocrystal formation rate. It could be concluded that the cocrystal formation rate increased with the increase of suspension density of raw materials. Further under the same suspension density, higher temperature will accelerate theophylline-benzoic acid cocrystal formation. Meanwhile, various data from the cocrystallization process in cooling crystallization, including nucleation time, nucleation temperature and suitable cooling ending point can be gained from results of on-line Raman monitoring.

Influence of Sample Preparation on Intrinsic Stress Inside a Model Chip—Comparison of Results from Electric Read-Out and Raman Spectroscopy

2017 ◽  
Author(s):  
T. Schaffus ◽  
H. Pfaff ◽  
P. Albert ◽  
M. Schaffus ◽  
F. Kroninger ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Sample Preparation ◽  
Intrinsic Stress ◽  
Stress Monitoring ◽  
Preparation Methods ◽  
Comparison Of Results ◽  
The Given

Abstract The given project is to benchmark typical preparation methods under the aspect of the influence of initial intrinsic stresses inside electric components. Raman spectroscopy has been applied as well as the piezo resistive readout on a specifically designed model stress monitoring chip.

o-Alkylselenenylated Benzoic Acid Accesses Several Sites in Serum Albumin According to Fluorescence Studies, Raman Spectroscopy and Theoretical Simulations

2013 ◽  
Vol 20 (6) ◽  
pp. 705-714 ◽  
Author(s):  
Federico Martinez-Ramos ◽  
Yadira Fonseca-Sabater ◽  
Marvin A. Soriano-Ursua ◽  
Eduardo Torres ◽  
Martha C. Rosales-Hernandez ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Benzoic Acid ◽  
Serum Albumin ◽  
Fluorescence Studies ◽  
Theoretical Simulations

scholarly journals Review on stationary phases and coating methods of MEMs gas chromatography columns

2020 ◽  
Vol 39 (1) ◽  
pp. 247-259
Author(s):  
Liu Yang ◽  
Molin Qin ◽  
Junchao Yang ◽  
Genwei Zhang ◽  
Jiana Wei
Keyword(s):  
Gas Chromatography ◽  
Microelectromechanical Systems ◽  
Stationary Phases ◽  
Preparation Methods ◽  
Site Analysis ◽  
Advantages And Disadvantages ◽  
Coating Methods ◽  
On Line ◽  
Inorganic Adsorbents ◽  
Gas Chromatography Columns

Abstract Gas chromatography (GC) is an important and widely used technique for separation and analysis in the field of analytical chemistry. Micro gas chromatography has been developed in response to the requirement for on-line analysis and on-site analysis. At the core of micro gas chromatography, microelectromechanical systems (MEMs) have the advantages of small size and low power consumption. This article introduces the stationary phases of micro columns in recent years, including polymer, carbon materials, silica, gold nanoparticles, inorganic adsorbents and ionic liquids. Preparation techniques ranging from classical coating to unusual sputtering of stationary phases are reviewed. The advantages and disadvantages of different preparation methods are analyzed. The paper introduces the separation characteristics and application progress of MEMs columns and discusses possible developments.

On-Line Monitoring of Airborne Chemistry in Levitated Nanodroplets:  In Situ Synthesis and Application of SERS-Active Ag−Sols for Trace Analysis by FT-Raman Spectroscopy

2003 ◽  
Vol 75 (9) ◽  
pp. 2166-2171 ◽  
Author(s):  
Nicolae Leopold ◽  
Michael Haberkorn ◽  
Thomas Laurell ◽  
Johan Nilsson ◽  
Josefa R. Baena ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Trace Analysis ◽  
In Situ Synthesis ◽  
Ft Raman Spectroscopy ◽  
On Line ◽  
Ft Raman

scholarly journals Combining Mechanistic Modeling and Raman Spectroscopy for Monitoring Antibody Chromatographic Purification

Processes ◽  
2019 ◽  
Vol 7 (10) ◽  
pp. 683 ◽  
Author(s):  
Feidl ◽  
Garbellini ◽  
Luna ◽  
Vogg ◽  
Souquet ◽  
...  
Keyword(s):  
Experimental Data ◽  
Raman Spectroscopy ◽  
Estimation Procedure ◽  
Mechanistic Modeling ◽  
Spectroscopic Techniques ◽  
Chromatographic Purification ◽  
On Line ◽  
Filter Approach ◽  
Underlying Mechanisms ◽  
Combining Information

Chromatography is widely used in biotherapeutics manufacturing, and the corresponding underlying mechanisms are well understood. To enable process control and automation, spectroscopic techniques are very convenient as on-line sensors, but their application is often limited by their sensitivity. In this work, we investigate the implementation of Raman spectroscopy to monitor monoclonal antibody (mAb) breakthrough (BT) curves in chromatographic operations with a low titer harvest. A state estimation procedure is developed by combining information coming from a lumped kinetic model (LKM) and a Raman analyzer in the frame of an extended Kalman filter approach (EKF). A comparison with suitable experimental data shows that this approach allows for the obtainment of reliable estimates of antibody concentrations with reduced noise and increased robustness.

Sol-Gel Synthesis and Characterization of Ultrafine ZrSiO4 Powder

2014 ◽  
Vol 906 ◽  
pp. 66-71
Author(s):  
Zhen Quan Li ◽  
Qiang Zhen ◽  
Ya Li Wang
Keyword(s):  
Wavelength Range ◽  
High Purity ◽  
Raw Materials ◽  
Formation Rate ◽  
Sol Gel ◽  
Molar Ratio ◽  
Sem And Tem ◽  
Homogeneous Product ◽  
Sol Gel Synthesis ◽  
Calcined Temperature

High purity ZrSiO4 powder were synthesized using Si (C2H5O)4 and ZrOCl2·8H2O as raw materials by the sol-gel method, LiCl was added as mineralizer to promote crystallization of zircon. The influences of molar ratio of Zr:Si, calcined time and calcined temperature on the synthesis of ZrSiO4 powder were investigated. XRD, SEM and TEM were used to characterize the powders. It was found that when the molar ratio of Zr:Si was 1:1.2, the calcined temperature was 1600°C and the calcined time was 4h, the high purity ZrSiO4 ultrafine powder was obtained. The ZrSiO4 formation began at 1300°C and when the gel was calcined at 1600°Cfor 4 h, the formation rate of ZrSiO4 was up to 95%. SEM and TEM studies reveal a homogeneous product with particle sizes on the order of 0.1-1μm. The IR emissivity of ultrafine ZrSiO4 is 0.892 at the whole wavelength range, and that is up to 0.951 at the wavelength range of 8-14 μm.

Microemulsion copolymerization of styrene-methyl methacrylate followed on line by low-resolution Raman spectroscopy

2009 ◽  
Vol 49 (11) ◽  
pp. 2125-2131 ◽  
Author(s):  
Miguel A. Corona-Rivera ◽  
Jorge Flores ◽  
Jorge E. Puig ◽  
Eduardo Mendizábal
Keyword(s):  
Raman Spectroscopy ◽  
Methyl Methacrylate ◽  
Low Resolution ◽  
On Line

Effects of raw materials and preparation methods of catalysts on the selective hydrogenation of ethyl phenylacetate

1996 ◽  
Vol 73 (4) ◽  
pp. 465-469 ◽  
Author(s):  
Kazuaki Ishii ◽  
Fujio Mizukami ◽  
Shu-ichi Niwa ◽  
Makoto Toba ◽  
Hirobumi Ushijima ◽  
...  
Keyword(s):  
Selective Hydrogenation ◽  
Raw Materials ◽  
Preparation Methods ◽  
Ethyl Phenylacetate

scholarly journals Identification of LDPE Grades Focusing on Specific CH2 Raman Vibration Modes

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Richard Jumeau ◽  
Patrice Bourson ◽  
Michel Ferriol ◽  
François Lahure ◽  
Marc Ponçot ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Raman Spectroscopy ◽  
Vibrational Spectroscopy ◽  
Phenomenological Model ◽  
Low Density ◽  
Vibration Modes ◽  
Scanning Calorimetry ◽  
Lamella Thickness ◽  
Poly Ethylene

The possibilities of applications of vibrational spectroscopy techniques (Raman spectroscopy) in the analysis and characterization of polymers are more and more used and accurate. In this paper, our purpose is to characterize Low Density Poly(Ethylene) (LDPE) grades by Raman spectroscopy and in particular with CH2 Raman vibration modes. With temperature measurements, we determine different amorphous and crystalline Raman assignments. From these results and on the basis of the evolution of CH2 bending Raman vibration modes, we develop a phenomenological model in correlation with Differential Scanning Calorimetry and in particular with crystalline lamella thickness determination.

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