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Prasad Tajpuriya G, Shah P, Shahi N, Bhattarai A. UV-Vis studies of methyl red in the presence of sodium dioctylsulfosuccinate/acetone and sodium dioctylsulfosuccinate/acetone/water. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 255:119646. [PMID: 33751959 DOI: 10.1016/j.saa.2021.119646] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 02/15/2021] [Accepted: 02/26/2021] [Indexed: 06/12/2023]
Abstract
This paper reports the spectra of methyl red (MR) in the presence of sodium dioctylsulfosuccinate (AOT) by UV-Vis spectrophotometer at 298.15 ± 0.1 K. The experiment shows the effect of acetone, AOT and water concentration on methyl red. The spectral study was based on R parameter, which is defined as [H2O]/[AOT]. The spectral study was possible in the range of R = 0-20 only because the solution appeared to be cloudy above this amount of water. When the concentration of AOT increased, the absorption of MR decreased, indicating a hypochromic shift, which is due to the interaction between AOT and MR. The absorbance increases with the increasing value of R, which indicates that the H2O molecule hinders the interactional forces between AOT and MR. The distribution constant was calculated by using nonlinear regression analysis and its variation with different R values indicate the effect of water content in the distribution behavior of MR in between the solvent and micellar region whereas the variation of the binding constant with different R values indicates the affinity of micelles to bind MR molecule. The study of this binding affinity will be very helpful in textile dyeing, decolorization of industrial effluents and development of azo-based molecules in novel photonic and optoelectronic devices.
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Affiliation(s)
| | - Pawan Shah
- Department of Chemistry, M.M.A.M.C, Tribhuvan University, Biratnagar, Nepal
| | - Neelam Shahi
- Department of Chemistry, M.M.A.M.C, Tribhuvan University, Biratnagar, Nepal
| | - Ajaya Bhattarai
- Department of Chemistry, M.M.A.M.C, Tribhuvan University, Biratnagar, Nepal.
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Wells N, Yusufu D, Mills A. Colourimetric plastic film indicator for the detection of the volatile basic nitrogen compounds associated with fish spoilage. Talanta 2018; 194:830-836. [PMID: 30609612 DOI: 10.1016/j.talanta.2018.11.020] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 11/03/2018] [Accepted: 11/05/2018] [Indexed: 11/30/2022]
Abstract
The first example of an extruded polymer film containing the pH sensitive dye bromophenol blue (BPB) is described in which the polymer encapsulated dye changes colour from yellow to blue upon exposure to basic volatile nitrogen compounds, such as those given off by fish as it spoils. The latter include: trimethylamine (TMA), dimethylamine (DMA) and ammonia (NH3), and are collectively known as total volatile basic nitrogen (TVB-N). The films' colourimetric response to specific levels of TMA, as measured using absorbance spectroscopy and digital photography coupled with RGB colour analysis, is reported. The indicator is then used as a fish spoilage indicator at 22 and 4 °C, whilst at the same time a microbiological study is carried out, and in both cases the results reveal a strong correlation between the change in colour of the indicator with the concentration of bacterial colony forming units on the fish; the latter is often used as a measure of fish freshness. The correlation arises because the increase in TVB-N in head space of the package is due to the gradual bacteria-induced decomposition of the fish. The colourimetric TVB-N plastic film indicator's potential as a spoilage indicator for packaged fresh fish is discussed briefly.
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Affiliation(s)
- Nathan Wells
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, UK
| | - Dilidaer Yusufu
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, UK
| | - Andrew Mills
- School of Chemistry and Chemical Engineering, Queen's University Belfast, Stranmillis Road, Belfast BT9 5AG, UK.
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Dittmar S, Zietzschmann F, Mai M, Worch E, Jekel M, Ruhl AS. Simulating Effluent Organic Matter Competition in Micropollutant Adsorption onto Activated Carbon Using a Surrogate Competitor. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:7859-7866. [PMID: 29890066 DOI: 10.1021/acs.est.8b01503] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Adsorption onto activated carbon is a promising option for removing organic micropollutants (OMPs) from wastewater treatment plant (WWTP) effluents. The heterogeneity of activated carbons and adsorption competition between OMPs and adsorbable compounds of the effluent organic matter (EfOM) complicate the prediction of OMP removals. Thus, reliable and simple test systems are desirable. For this study, batch experiments with powdered activated carbon (PAC) were carried out to examine methyl orange (MO) as a selected surrogate competitor to simulate EfOM adsorption competition. MO solutions were spiked with carbamazepine (CBZ) as an indicator substance for well-adsorbing OMPs. On the basis of CBZ adsorption isotherms in WWTP effluents, MO concentrations for batch test solutions with identical adsorption competition toward CBZ were calculated. The calculations were performed according to an empirical model of CBZ adsorption in the presence of MO, since predictions employing the ideal adsorbed solution theory (IAST) proved to be inaccurate. Comparative batch tests with five different PACs were conducted with WWTP effluent and respective MO batch test solutions. Except for one PAC, the achieved CBZ removals were very similar in WWTP effluent and the test solution. Additionally, a universal correlation between MO and CBZ removals was found for four PACs.
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Affiliation(s)
- Stefan Dittmar
- Technische Universität Berlin , Chair of Water Quality Control , Sekr. KF4, Straße des 17. Juni 135 , 10623 Berlin , Germany
| | - Frederik Zietzschmann
- Technische Universität Berlin , Chair of Water Quality Control , Sekr. KF4, Straße des 17. Juni 135 , 10623 Berlin , Germany
| | - Maike Mai
- Technische Universität Berlin , Chair of Soil Science , Sekr. BH 10-1, Straße des 17. Juni 135 , 10623 Berlin , Germany
| | - Eckhard Worch
- Technische Universität Dresden, Institute of Water Chemistry , 01062 Dresden , Germany
| | - Martin Jekel
- Technische Universität Berlin , Chair of Water Quality Control , Sekr. KF4, Straße des 17. Juni 135 , 10623 Berlin , Germany
| | - Aki S Ruhl
- Technische Universität Berlin , Chair of Water Quality Control , Sekr. KF4, Straße des 17. Juni 135 , 10623 Berlin , Germany
- German Environment Agency (UBA) , Section II 3.1, Schichauweg 58 , 12307 Berlin , Germany
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Shokrollahi A, Zare E. Determination of acidity constants of bromophenol blue and phenol red indicators by solution scanometric method and comparison with spectrophotometric results. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.01.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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5
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Babamoradi H, Abdollahi H. Study of monoprotic acid-base equilibria in aqueous micellar solutions of nonionic surfactants using spectrophotometry and chemometrics. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2015; 149:851-859. [PMID: 26002436 DOI: 10.1016/j.saa.2015.04.091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2014] [Revised: 04/20/2015] [Accepted: 04/22/2015] [Indexed: 06/04/2023]
Abstract
Many studies have shown the distribution of solutes between aqueous phase and micellar pseudo-phase in aqueous micellar solutions. However, spectrophotometric studies of acid-base equilibria in these media do not confirm such distribution because of the collinearity between concentrations of chemical species in the two phases. The collinearity causes the number of detected species to be equal to the number of species in a homogenous solution that automatically misinterpreted as homogeneity of micellar solutions, therefore the collinearity is often neglected. This interpretation is in contradiction to the distribution theory in micellar media that must be avoided. Acid-base equilibrium of an indicator was studied in aqueous micellar solutions of a nonionic surfactant to address the collinearity using UV/Visible spectrophotometry. Simultaneous analysis (matrix augmentation) of the equilibrium and solvation data was applied to eliminate the collinearity from the equilibrium data. A model was then suggested for the equilibrium that was fitted to the augmented data to estimate distribution coefficients of the species between the two phases. Moreover, complete resolution of concentration and spectral profiles of species in each phase was achieved.
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Affiliation(s)
- Hamid Babamoradi
- University of Copenhagen, Faculty of Science, Department of Food Science, Spectroscopy & Chemometrics Section, Rolighedsvej 30, DK-1958 Frederiksberg, Denmark.
| | - Hamid Abdollahi
- Institute for Advanced Studies in Basic Sciences (IASBS), Department of Chemistry, 45137-66731 Zanjan, Iran
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Klučáková M, Kolajová R. Dissociation ability of humic acids: Spectroscopic determination of pKa and comparison with multi-step mechanism. REACT FUNCT POLYM 2014. [DOI: 10.1016/j.reactfunctpolym.2014.02.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Momeni-Isfahani T, Niazi A. Spectrophotometric determination of acidity constants of 2-(2-Thiazolylazo)-Cresol in various water-organic solvent media mixtures using chemometrics methods. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 120:630-635. [PMID: 24291515 DOI: 10.1016/j.saa.2013.11.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 11/01/2013] [Accepted: 11/05/2013] [Indexed: 06/02/2023]
Abstract
The combination of soft- and hard-modeling was used to the spectrophotometric studies of the acidity constants of 2-(2-Thiazolylazo)-Cresol (TAC) at 25°C and at ionic strength 0.1 mol L(-1) in pure water as well as in aqueous media containing variable percentages (10-50%) of organic solvents. The organic solvents used were methanol, ethanol, dimethyl formamide (DMF) and 1,4-dioxane. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program was applied for determining acidity constants and pure spectra of different form of TAC. Results show that the acidity constants of TAC are influenced as the percentages of solvents added to the solution. The corresponding pKa values in solvent-water mixtures were determined. There are linear relationships between acidity constants and the mole fraction of organic solvents in the solvent mixtures. The effects of various solvents on absorption properties and acidity constants of each component are also discussed.
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Affiliation(s)
- Tahereh Momeni-Isfahani
- Department of Chemistry, Faculty of Science, Islamic Azad University, Arak Branch, Arak, Iran
| | - Ali Niazi
- Department of Chemistry, Faculty of Science, Islamic Azad University, Arak Branch, Arak, Iran.
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Equilibrium and Structural Study of m-Methyl Red in Aqueous Solutions: Distribution Diagram Construction. J SOLUTION CHEM 2013. [DOI: 10.1007/s10953-013-0068-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sıdır İ, Gülseven Sıdır Y, Berber H. Acidity constant determination of novel drug precursor benzothiazolon derivatives including acyl and piperazine moieties. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 111:211-216. [PMID: 23644445 DOI: 10.1016/j.saa.2013.03.071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Revised: 06/07/2012] [Accepted: 03/16/2013] [Indexed: 06/02/2023]
Abstract
In this study, protonation and deprotonation behaviors of eight new drug precursor benzothiazolon derivatives in all of acidic and basic scale (super acidic, pH, super basic regions) are analyzed by using UV-visible spectrophotometric technique. Acidity constants (pKa), elucidation of the structure and protonation mechanisms of the studied molecules are obtained. Substituent effect on acidity constant values is discussed. These molecules are protonated from oxygen atom of acetamide group in the keto form. The protonation is found to be considerably contributed by the keto form.
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Affiliation(s)
- İsa Sıdır
- Bitlis Eren University, Faculty of Arts & Science, Department of Physics, 13000 Bitlis, Turkey.
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Benvidi A, Heidari F, Tabaraki R, Mazloum-Ardakani M. Application of principal component-wavelet neural network in spectrophotometric determination of acidity constants of 4-(2-thiazolylazo)-resorcinol. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2011; 78:1380-1385. [PMID: 21354857 DOI: 10.1016/j.saa.2011.01.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2010] [Revised: 01/05/2011] [Accepted: 01/17/2011] [Indexed: 05/30/2023]
Abstract
The acidity constants of 4-(2-thiazolylazo)-resorcinol (TAR) were determined by the principal component-wavelet neural network (WNN). Biprotic acid mass balance equations, the distribution functions and the corresponding spectral profiles which were generated by a Gaussian model, have been considered to simulate all required absorbance-pH data. The simulated absorption-pH data matrix was used as training set whereas the TAR absorption-pH data was used as the test set of WNN model. The obtained acidity constants were in good agreement with the reported values of acidity constants in the literature and with those calculated by DATAN software. Artificial neural network (ANN) model has been also employed in this study and the results of WNN were compared with those obtained by ANN. It was found that WNN gives faster convergence and slightly better accuracy.
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Affiliation(s)
- Ali Benvidi
- Department of Chemistry, Yazd University, Yazd, Iran.
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Abdollahi H, Golshan A. Rank annihilation factor analysis method for spectrophotometric study of second-order reaction kinetics. Anal Chim Acta 2011; 693:26-34. [PMID: 21504807 DOI: 10.1016/j.aca.2011.03.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 03/04/2011] [Accepted: 03/09/2011] [Indexed: 11/18/2022]
Abstract
In this study several methods are described to determine the rate constant of a second-order reaction in the form of A+B→C. These approaches allow circumventing a rank deficiency inherent of a second-order reaction when the spectroscopic data is influenced by additional source of variance. Classically, to determine the unknown rate constant in this kind of systems, one needs to have extra knowledge about the system, including the spectra of the reactants or product and the exact kinetics. In the case of the presence of an unknown phenomenon in the data set that cannot be explained by the model, such as baseline drift, the estimated rate constant might be erroneous. Present work is a modification of the rank annihilation factor analysis (RAFA) algorithm by inclusion of I) pure spectra of reactants, or IIA) mean centering step, or IIB) mean spectrum. The proposed methods can interestingly be applied on a single kinetic run. The performances of the new methods have been evaluated by applying them to analysis of simulated and experimental data.
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Affiliation(s)
- Hamid Abdollahi
- Department of Chemistry, Institute for Advanced Studies in Basic Sciences, Zanjan, Iran.
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Ebead Y. The role of the medium on the acid dissociation constants of some azo dyes in view of experimental and theoretical data. J Mol Struct 2010. [DOI: 10.1016/j.molstruc.2010.08.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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13
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Rank annihilation factor analysis using mean centering of ratio spectra for kinetic–spectrophotometric analysis of unknown samples. Anal Chim Acta 2009; 639:19-28. [DOI: 10.1016/j.aca.2009.02.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Revised: 01/26/2009] [Accepted: 02/16/2009] [Indexed: 11/23/2022]
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