Rank deficiency in spectrophotometric study of acid dissociation equilibria in mixed solvent media

Abdollahi, Hamid; Babamoradi, Hamid

doi:10.1016/j.chemolab.2009.04.010

Cited by 4 publications

(5 citation statements)

References 32 publications

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“…Typically, this approach can be conducted in one of the two main ways of spectra-wise or concentration-wise augmentation. 21 Rank analysis of the NR titration data in an M-W mixture revealed just two important eigenvalues regarding the collinearity of the concentration profiles. Consequently, in this system, parameter fitting and recovering the true profiles of concentration can be performed successfully.…”

Section: Matrix Augmentationmentioning

confidence: 98%

“…Matrix augmentation can be described as coupling data matrices, which are related to the different systems with common chemical species. Typically, this approach can be conducted in one of the two main ways of spectra‐wise or concentration‐wise augmentation . Rank analysis of the NR titration data in an M‐W mixture revealed just two important eigenvalues regarding the collinearity of the concentration profiles.…”

Section: Theorymentioning

confidence: 99%

See 1 more Smart Citation

Hard modeling study of chemical equilibria in mixed solvents

Sheykhizadeh

Naseri

Abdollahi

2018

Journal of Chemometrics

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In many years, intensive researches have focused on studying the chemical equilibria like complex formation and acid‐base titration in different solvent mixtures, such as methanol‐water. In this respect, it has been revealed that methanol‐water mixture is not a simple homogenous ideal mixture and it contains clusters of pure water (W), pure methanol (M), and associated methanol‐water molecules (MW) with a certain association constant that the solute can distribute among these clusters. To describe solute distribution in this chemical system, an exhausted model has been introduced, which is extended herein to illustrate the distribution of a solute with acid‐base behavior, ie, the neutral red indicator. Since it is imperative to determine the association constant of the solvents and the distribution constants of the solute for calculation of the solute's protonation constant in the mixture, this work employs UV‐vis spectrophotometry as a fast and convenient technique to calculate all these parameters. For this purpose, protonated and deprotonated forms of neutral red are monitored in various water‐methanol compositions. Moreover, the acid‐base equilibrium of neutral red in definite compositions of the solvent mixture is investigated using the data obtained from acid‐base titrations. Finally, the protonation constant of neutral red in MW clusters is determined by analyzing the titration data of three methanol‐water compositions after matrix augmentation and elimination of rank deficiency.

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Section: Matrix Augmentationmentioning

confidence: 98%

Section: Theorymentioning

confidence: 99%

Hard modeling study of chemical equilibria in mixed solvents

Sheykhizadeh

Naseri

Abdollahi

2018

Journal of Chemometrics

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“…They published these two works in one of the top chemistry journals, Analytical Chemistry [3,4]. The research group of Abdollahi has developed different factor analysis-based curve resolution methods to resolve different chemical systems [27][28][29][30][31]. Tautomerization equilibria in aqueous micellar solutions and acid dissociation equilibria in mixed solvent media were studied using factor analysis methods by this group [27,29,32].…”

Section: Multivariate Curve Resolution and Factor Analysismentioning

confidence: 99%

“…The research group of Abdollahi has developed different factor analysis-based curve resolution methods to resolve different chemical systems [27][28][29][30][31]. Tautomerization equilibria in aqueous micellar solutions and acid dissociation equilibria in mixed solvent media were studied using factor analysis methods by this group [27,29,32]. They also studied multicomponent simultaneous equilibria using self-modeling methods [28,30].…”

Section: Multivariate Curve Resolution and Factor Analysismentioning

confidence: 99%

A perspective on the growth of chemometrics in Iran: a glance into activities between 2005 and 2012

Naseri

Bahram

2013

Journal of Chemometrics

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Although the first publications in the field of chemometrics by Iranian researchers go back nearly 23 years, Iran's chemometrics has experienced significant growth after the year 2000. More than 1500 papers have been published by Iranian chemometricians between 2005 and 2012 which is about seven times more than those published before 2005. The aim of this review is to present a perspective about Iran's chemometrics developments. The role of enthusiastic students, motivated professors, annual workshops, and international collaborations is discussed in this work. After introducing the first papers in each field of chememotrics, the papers published during 2005–2012 were screened, and some of them were introduced. Copyright © 2013 John Wiley & Sons, Ltd.

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“…Thus, matrix augmentation strategy can become in an easy, versatile, and intelligent way to break rank deficiency (i.e. appending one or more full rank data sets to the rank deficient matrix) [47]. Consequently, the spectral augmentation mode was used when applying the MCR-ALS algorithm.…”

Section: Introductionmentioning

confidence: 99%