scholarly journals Direct Analysis in Real Time by Mass Spectrometric Technique for Determining the Variation in Metabolite Profiles ofCinnamomum tamalaNees and Eberm Genotypes

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Vineeta Singh ◽  
Atul Kumar Gupta ◽  
S. P. Singh ◽  
Anil Kumar

Cinnamomum tamalaNees & Eberm. is an important traditional medicinal plant, mentioned in various ancient literatures such as Ayurveda. Several of its medicinal properties have recently been proved. To characterize diversity in terms of metabolite profiles ofCinnamomum tamalaNees and Eberm genotypes, a newly emerging mass spectral ionization technique direct time in real time (DART) is very helpful. The DART ion source has been used to analyze an extremely wide range of phytochemicals present in leaves ofCinnamomum tamala. Ten genotypes were assessed for the presence of different phytochemicals. Phytochemical analysis showed the presence of mainly terpenes and phenols. These constituents vary in the different genotypes ofCinnamomum tamala. Principal component analysis has also been employed to analyze the DART data of theseCinnamomumgenotypes. The result shows that the genotype ofCinnamomum tamalacould be differentiated using DART MS data. The active components present inCinnamomum tamalamay be contributing significantly to high amount of antioxidant property of leaves and, in turn, conditional effects for diabetic patients.

2017 ◽  
Vol 17 (4) ◽  
pp. 850-868 ◽  
Author(s):  
William Soo Lon Wah ◽  
Yung-Tsang Chen ◽  
Gethin Wyn Roberts ◽  
Ahmed Elamin

Analyzing changes in vibration properties (e.g. natural frequencies) of structures as a result of damage has been heavily used by researchers for damage detection of civil structures. These changes, however, are not only caused by damage of the structural components, but they are also affected by the varying environmental conditions the structures are faced with, such as the temperature change, which limits the use of most damage detection methods presented in the literature that did not account for these effects. In this article, a damage detection method capable of distinguishing between the effects of damage and of the changing environmental conditions affecting damage sensitivity features is proposed. This method eliminates the need to form the baseline of the undamaged structure using damage sensitivity features obtained from a wide range of environmental conditions, as conventionally has been done, and utilizes features from two extreme and opposite environmental conditions as baselines. To allow near real-time monitoring, subsequent measurements are added one at a time to the baseline to create new data sets. Principal component analysis is then introduced for processing each data set so that patterns can be extracted and damage can be distinguished from environmental effects. The proposed method is tested using a two-dimensional truss structure and validated using measurements from the Z24 Bridge which was monitored for nearly a year, with damage scenarios applied to it near the end of the monitoring period. The results demonstrate the robustness of the proposed method for damage detection under changing environmental conditions. The method also works despite the nonlinear effects produced by environmental conditions on damage sensitivity features. Moreover, since each measurement is allowed to be analyzed one at a time, near real-time monitoring is possible. Damage progression can also be given from the method which makes it advantageous for damage evolution monitoring.


Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2473
Author(s):  
Julia C. Steinbach ◽  
Markus Schneider ◽  
Otto Hauler ◽  
Günter Lorenz ◽  
Karsten Rebner ◽  
...  

The chemical synthesis of polysiloxanes from monomeric starting materials involves a series of hydrolysis, condensation and modification reactions with complex monomeric and oligomeric reaction mixtures. Real-time monitoring and precise process control of the synthesis process is of great importance to ensure reproducible intermediates and products and can readily be performed by optical spectroscopy. In chemical reactions involving rapid and simultaneous functional group transformations and complex reaction mixtures, however, the spectroscopic signals are often ambiguous due to overlapping bands, shifting peaks and changing baselines. The univariate analysis of individual absorbance signals is hence often only of limited use. In contrast, batch modelling based on the multivariate analysis of the time course of principal components (PCs) derived from the reaction spectra provides a more efficient tool for real-time monitoring. In batch modelling, not only single absorbance bands are used but information over a broad range of wavelengths is extracted from the evolving spectral fingerprints and used for analysis. Thereby, process control can be based on numerous chemical and morphological changes taking place during synthesis. “Bad” (or abnormal) batches can quickly be distinguished from “normal” ones by comparing the respective reaction trajectories in real time. In this work, FTIR spectroscopy was combined with multivariate data analysis for the in-line process characterization and batch modelling of polysiloxane formation. The synthesis was conducted under different starting conditions using various reactant concentrations. The complex spectral information was evaluated using chemometrics (principal component analysis, PCA). Specific spectral features at different stages of the reaction were assigned to the corresponding reaction steps. Reaction trajectories were derived based on batch modelling using a wide range of wavelengths. Subsequently, complexity was reduced again to the most relevant absorbance signals in order to derive a concept for a low-cost process spectroscopic set-up which could be used for real-time process monitoring and reaction control.


2012 ◽  
Vol 70 (15) ◽  
pp. 1650 ◽  
Author(s):  
Qing Yu ◽  
Binbin Yu ◽  
Hao Yue ◽  
Lili Jiao ◽  
Shuying Liu
Keyword(s):  

2017 ◽  
Vol 9 (34) ◽  
pp. 5065-5074 ◽  
Author(s):  
Kathleen T. Upton ◽  
Katherine A. Schilling ◽  
J. L. Beauchamp

The EZ-DART ion source for ambient mass spectrometry, with simplified construction, minimal assembly cost, and versatile sampling capabilities, is described.


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