Detection and Identification of a Methanol−Water Complex by Factor Analysis of Infrared Spectra

Zhao, Zhouming; Malinowski, Edmund R.

doi:10.1021/ac9809480

Cited by 53 publications

(49 citation statements)

References 16 publications

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“…Among the chemometrics works for characterization of methanol-water association by using of the spectroscopic data, Zhao and Malinowski [13] deduced a MW 2 stoichiometry for the methanol-water association and calculated equilibrium constant equal to 306 for dissociation of this complex. Since the stoichiometry is not similar to the present work, the equilibrium constants cannot be compared.…”

Section: Resultsmentioning

confidence: 99%

“…In the TFA procedure, a transformation matrix, T, is calculated by projection of the concentration matrix, X, on the matrix spaces of the row matrix (R). Premultiplying the column matrix (C) by T gives the pure thermodynamic properties, Y (Equations (11)(12)(13). The resulted thermodynamic properties in the pure solvent clusters are listed in Table IV.…”

Section: Resultsmentioning

confidence: 99%

“…Based on the better fitting of the double association model to the experimental data, they proposed the presence of four species in menthol-water mixtures consisting pure methanol and water and two methanol-water clusters (1:1 and 1:5 methanol to water complexes). Zhao and Malinowski [13] investigated the methanol-water mixtures by windows factor analysis (WFA) of the FT-IR absorption spectra. Three principal factors were detected and a 1:2 MW was though to be the main complex species.…”

Section: Introductionmentioning

confidence: 99%

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Characterization and prediction of solute properties in methanol–water association by chemometrics analysis of solvation data

Hemmateenejad

2005

Journal of Chemometrics

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Methanol-water binary mixtures have been characterized as a ternary or quaternary system composed of unassociated methanol (M) and water (W) and one or two methanol-water complex (MW). Identification of the methanol-water association was performed by chemometrics analysis of some solvent-related properties of binary methanol-water mixtures with compositions between 0 and 100% volume percent of methanol. Abstract factor analysis of the solvation data identified three chemical species in the solvent mixtures that can be attributed to the pure methanol and water solvents and a MW association. The stoichiometric molar ratio of the W:M associate was investigated by the multivariate curve resolution-alternative least squares (MCR-ALS) of the solvation data and the resulted concentration profiles of the solvent species implied a 1:1 molar ratio for the M:W association. The equilibrium constant of the formation of the M-W association was determined by MCR-ALS and iterative rank annihilation factor analysis (RAFA) to be equal to 13.72. The solvation data of the pure M-W cluster was calculated by target factor analysis (TFA) procedure. Higher hydrogen-bond basicity and lower hydrogen-bond acidity was obtained for the MW solvent in comparison with both the M and W solvents. The proposed model was employed to calculate the acidity constant and HPLC capacity factors of some solutes in the MW cluster. Interestingly, the solutes were found to be stronger acid in relative to pure methanol and water. Finally, the specific solute-solvent interactions and preferential solvation of the solutes were explained by the nonmodeled solute-related data.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Characterization and prediction of solute properties in methanol–water association by chemometrics analysis of solvation data

Hemmateenejad

2005

Journal of Chemometrics

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“…03, pp. 677 -682, July -September, 2013 methanol molecules according to the following dynamic equilibrium (Zhao et al, 1999):…”

Section: Resultsmentioning

confidence: 99%

“…In fact, experimental studies supported by computational investigations have been used to study the microscopic structure of this type of system, where clusters are formed between like and/or unlike molecules (Mikhail and Kimel, 1961;Zhao and Malinowski, 1999;Yilmaz, 2002;Gonzalez-Salgado and Nezbeda, 2006). In this type of system, the interaction between unlike molecules can be quantified from viscosity measurements and by calculating the Grumberg-Nissan constant d' (Grumberg and Nissan, 1949).…”

Section: Introductionmentioning

confidence: 99%

Influence of polyvinylpyrrolidone on the interaction between water and methanol

Guettari

Gomati

2013

Braz. J. Chem. Eng.

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-The present work aims to determine the influence of a dissolved polymer, polyvinylpyrrolidone, on the interaction between water and methanol. First, the dynamic viscosities were measured for polymer solutions by a rotational concentric cylinder at 25 °C and for the polymer concentration range from 0.1 to 0.6 g/dl. The results show a polynomial dependence of the viscosity on polymer concentration. On the hypothesis of a quasi-binary system, a pseudo Grumberg-Nissan constant, ' p d , was introduced to quantify the interaction between unlike molecules in the presence of polymer. The interaction between unlike molecules due to the presence of the polymer was quantified by the deviation of the Grumberg-Nissan constant,Generally, this constant is negative which means that the interactions between water and methanol decrease in the presence of polyvinylpyrrolidone at 25 °C. The presence of the polymer induces a perturbation of the dynamic equilibrium between free and complexed molecules.

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Quantitative analysis of 17 amino acids in tobacco leaves using an amino acid analyzer and chemometric resolution

2015

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A method was developed for quantifying 17 amino acids in tobacco leaves by using an A300 amino acid analyzer and chemometric resolution. In the method, amino acids were eluted by the buffer solution on an ion-exchange column. After reacting with ninhydrin, the derivatives of amino acids were detected by ultraviolet detection. Most amino acids are separated by the elution program. However, five peaks of the derivatives are still overlapping. A non-negative immune algorithm was employed to extract the profiles of the derivatives from the overlapping signals, and then peak areas were adopted for quantitative analysis of the amino acids. The method was validated by the determination of amino acids in tobacco leaves. The relative standard deviations (n = 5) are all less than 2.54% and the recoveries of the spiked samples are in a range of 94.62-108.21%. The feasibility of the method was proved by analyzing the 17 amino acids in 30 tobacco leaf samples.

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Detection and Identification of a Methanol−Water Complex by Factor Analysis of Infrared Spectra

Cited by 53 publications

References 16 publications

Characterization and prediction of solute properties in methanol–water association by chemometrics analysis of solvation data

Characterization and prediction of solute properties in methanol–water association by chemometrics analysis of solvation data

Influence of polyvinylpyrrolidone on the interaction between water and methanol

Quantitative analysis of 17 amino acids in tobacco leaves using an amino acid analyzer and chemometric resolution

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