Applications of the electronic spectra of pyridine homologues to quantitative analysis and to the measurement of dissociation constants

1950 ◽  
Vol 9 ◽  
pp. 26 ◽  
Author(s):  
E. F. G. Herington
Keyword(s):  
Quantitative Analysis ◽  
Electronic Spectra ◽  
Dissociation Constants ◽  
Pyridine Homologues

Pyridyl enamines and dienamines as models of mycobacterial pigments

1970 ◽  
Vol 23 (10) ◽  
pp. 2109 ◽  
Author(s):  
GM Renwick
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Electronic Spectra ◽  
Dissociation Constants ◽  
Related Compounds

N,N'-Tetramethylformamidinium perchlorate and its higher vinylogue react with 4-picolylsodium to yield 4-(2-dimethylaminovinyl)pyridine (1) and l-dimethyl-amino-4-(4-pyridyl)buta-1,3-diene (3), and with 2-picolylsodium to yield the 2-pyridine isomers (2) and (4). The N.M.R. spectra and dissociation constants of these products are reported. The electronic spectra of the bases, their mono- and di-cations, and of some related compounds are described, and comparisons are drawn with coloured alkaloids which are produced by Mycobacterium tuberculosis in the presence of isonicotinoylhydrazide.

Study of porous cellulose beads as a dye-ligand matrix. Effect of protein admixtures and concentration of immobilized dye in the quantitative analysis of lactate dehydrogenase: Cibacron blue interaction

1990 ◽  
Vol 55 (2) ◽  
pp. 581-586 ◽  
Author(s):  
Danica Mislovičová ◽  
Peter Gemeiner ◽  
Viera Ďurišová
Keyword(s):  
Quantitative Analysis ◽  
Lactate Dehydrogenase ◽  
Matrix Effect ◽  
Dissociation Constants ◽  
Cibacron Blue ◽  
Blue Dextran ◽  
Nonspecific Interaction ◽  
The Matrix ◽  
Bead Cellulose ◽  
Total Interaction

The effect of protein admixtures and concentration of immobilized dye on the interaction of lactate dehydrogenase (LDH) with Cibacron Blue-bead cellulose has been studied by means of zonal chromatography with Cibacron Blue-dextran T 10 as the mobile ligand. The influence of both variables on the values of dissociation constants of complexes immobilized dye-LDH (KI-L) and mobile dye-LDH (KM-L) can be summarized as follows: The values of KI-L remained practically constant and were found to be lower than those of KM-L. The differences found in KI-L and KM-L values should help to estimate the contribution of nonspecific interaction of the matrix to the total interaction between dye-ligand and the enzyme.

scholarly journals Difluoroboron Curcumin Complex: A Study on Determination of Acidity Constants and Quantitative Analysis of Arsenic(III)

2021 ◽  
Vol 21 (5) ◽  
pp. 1271
Author(s):  
Nguyen Quoc Thang ◽  
Tran Nguyen Minh An ◽  
Le Thi Thanh Tran ◽  
Do Tam Nhan ◽  
Mai Ngoc Tan ◽  
...  
Keyword(s):  
Quantitative Analysis ◽  
Boron Trifluoride ◽  
Dissociation Constants ◽  
Limit Of Detection ◽  
High Accuracy ◽  
The Other ◽  
Total Arsenic ◽  
Acidity Constants ◽  
Limit Of Quantification

In this study, the complex of difluoroboron, curcumin (BF2-Cur), has been synthesized and characterized via the combination of Boron trifluoride-diethyl etherate ((C2H5)2OBF3) and curcumin. However, the new dissociation constants, pKa1 and pKa2 of the BF2-Cur complex, have been indicted by the values of 8.44 ± 0.16 and 9.76 ± 0.13, respectively. On the other hand, the reagent was also used to determine As(III) in aqueous solutions by UV–Vis spectrophotometry. As a result, the method was validated for accuracy, precision, linearity, and sensitivity, and the linear range was from 1.0 to 25.0 µmol/L, with the linear regression, A = 0.0027 C + 0.0106, correlation coefficient R2 = 0.9969. Besides, the limit of detection (LOD) and limit of quantification (LOQ) were determined as 0.83 and 2.10 µmol/L, respectively. Thus, the developed method is successfully used for quantitative analysis of total arsenic in wastewater by reducing As(V) to As(III), then determining As(III) with high accuracy results.

An Improved Quantitative Image Analyser

1977 ◽  
Vol 35 ◽  
pp. 226-227
Author(s):  
J.P. Fallon ◽  
P.J. Gregory ◽  
C.J. Taylor
Keyword(s):  
Feature Extraction ◽  
Quantitative Analysis ◽  
Frequency Content ◽  
General Sense ◽  
Physical Measurements ◽  
Quantitative Image ◽  
Image Analyser ◽  
Automatic Methods ◽  
Quantitative Results

Quantitative image analysis systems have been used for several years in research and quality control applications in various fields including metallurgy and medicine. The technique has been applied as an extension of subjective microscopy to problems requiring quantitative results and which are amenable to automatic methods of interpretation.Feature extraction. In the most general sense, a feature can be defined as a portion of the image which differs in some consistent way from the background. A feature may be characterized by the density difference between itself and the background, by an edge gradient, or by the spatial frequency content (texture) within its boundaries. The task of feature extraction includes recognition of features and encoding of the associated information for quantitative analysis.Quantitative Analysis. Quantitative analysis is the determination of one or more physical measurements of each feature. These measurements may be straightforward ones such as area, length, or perimeter, or more complex stereological measurements such as convex perimeter or Feret's diameter.

Quantification of Silica Uptake by Alveolar Macrophages - An Emperical Scanning Electron Microprobe Method

1982 ◽  
Vol 40 ◽  
pp. 332-333
Author(s):  
V. V. Damiano ◽  
R. P. Daniele ◽  
H. T. Tucker ◽  
J. H. Dauber
Keyword(s):  
Quantitative Analysis ◽  
Alveolar Macrophages ◽  
Bulk Sample ◽  
Silica Particles ◽  
Empirical Method ◽  
Phagocytic Cells ◽  
Calibration Standards ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Scanning Electron

An important example of intracellular particles is encountered in silicosis where alveolar macrophages ingest inspired silica particles. The quantitation of the silica uptake by these cells may be a potentially useful method for monitoring silica exposure. Accurate quantitative analysis of ingested silica by phagocytic cells is difficult because the particles are frequently small, irregularly shaped and cannot be visualized within the cells. Semiquantitative methods which make use of particles of known size, shape and composition as calibration standards may be the most direct and simplest approach to undertake. The present paper describes an empirical method in which glass microspheres were used as a model to show how the ratio of the silicon Kα peak X-ray intensity from the microspheres to that of a bulk sample of the same composition correlated to the mass of the microsphere contained within the cell. Irregular shaped silica particles were also analyzed and a calibration curve was generated from these data.

Lateral resolution of the electron microbeam analysis

1978 ◽  
Vol 36 (1) ◽  
pp. 542-543
Author(s):  
H.J. Dudek
Keyword(s):  
Quantitative Analysis ◽  
Depth Resolution ◽  
Lateral Resolution ◽  
Cylindrical Particle ◽  
Correction Procedure ◽  
X Ray ◽  
Element Concentrations ◽  
Microbeam Analysis ◽  
The Matrix

The chemical inhomogenities in modern materials such as fibers, phases and inclusions, often have diameters in the region of one micrometer. Using electron microbeam analysis for the determination of the element concentrations one has to know the smallest possible diameter of such regions for a given accuracy of the quantitative analysis.In th is paper the correction procedure for the quantitative electron microbeam analysis is extended to a spacial problem to determine the smallest possible measurements of a cylindrical particle P of high D (depth resolution) and diameter L (lateral resolution) embeded in a matrix M and which has to be analysed quantitative with the accuracy q. The mathematical accounts lead to the following form of the characteristic x-ray intens ity of the element i of a particle P embeded in the matrix M in relation to the intensity of a standard S

An example of spectrum imaging used for comparison of EELS quantitative analysis techniques on Al-Li

1991 ◽  
Vol 49 ◽  
pp. 726-727
Author(s):  
John A. Hunt
Keyword(s):  
Quantitative Analysis ◽  
Large Data ◽  
Difference Spectrum ◽  
Large Data Sets ◽  
Foil Thickness ◽  
Data Sets ◽  
Analysis Techniques ◽  
Spectrum Imaging ◽  
Normal Spectrum ◽  
Electron Energy Loss

Spectrum-imaging is a useful technique for comparing different processing methods on very large data sets which are identical for each method. This paper is concerned with comparing methods of electron energy-loss spectroscopy (EELS) quantitative analysis on the Al-Li system. The spectrum-image analyzed here was obtained from an Al-10at%Li foil aged to produce δ' precipitates that can span the foil thickness. Two 1024 channel EELS spectra offset in energy by 1 eV were recorded and stored at each pixel in the 80x80 spectrum-image (25 Mbytes). An energy range of 39-89eV (20 channels/eV) are represented. During processing the spectra are either subtracted to create an artifact corrected difference spectrum, or the energy offset is numerically removed and the spectra are added to create a normal spectrum. The spectrum-images are processed into 2D floating-point images using methods and software described in [1].

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