Bromophenol Red Research Articles

UV−Curable choline chloride and bromophenol red covalent functionalized chitosan antibacterial and pH−sensitive hydrogels

Food safety and food freshness issues have become important concerns for consumers and hydrogels with high antibacterial efficiency, low toxicity and pH−sensitive colorimetric intelligence are one of candidates to meet the requirement of food package and food spoilage monitoring. Nevertheless, hydrogels prepared only by assembling the ingredients with non−covalent interactions through time−consuming molding process usually encounter drawbacks such as relatively poor mechanical properties, stability and thermal stability, which always restrict their further applications. To overwhelm these shortcomings, UV−curable choline chloride (ChCl) and bromophenol red (BR) covalent functionalized antibacterial and pH−sensitive cross−linked hydrogels (UV−hydrogels) were developed in this paper. The UV−hydrogels possessed good thermal stability because the initiated thermal decomposition temperature (Td5) is in the range of 135.8–184.7 °C. The DMA analysis revealed that the UV−hydrogels are with good mechanical properties because the elongation at break is in the range of 117–525% and the tensile strength is in the range of 0.8–2.7 MPa. The UV−hydrogels with BR groups exhibited naked eye visible color variation from yellow to dark blue-green with the variation of the pH values from 2 to 14. The antibacterial efficiency of the UV−hydrogels against S. aureus, E. coli and M. albican increased with the increment of covalent−grafted ChCl amount. Cytotoxicity assay demonstrated that the UV−hydrogels are low toxicity against L929 cells. The experiment of monitoring freshness of beef denoted the UV−hydrogels have potential application in animal–derived high protein food packaging and freshness monitoring.

IMPREGNATED FIBROUS CHEMISORBENTS FOR THE COLORIMETRIC DETECTION OF AMMONIA

The paper presents research results on the colorimetric behavior of impregnated fibrous chemisorbents (IFCS) of basic gases with visual identification of the dynamic absorption capacity “response” moment (IFCS-I) during the absorption of ammonia. Chemisorbents were obtained by impregnation of fibrous carriers with polybasic hydroxyl acid aqueous solutions with adding acid-base indicators (Ind). IFCS-I based on oxyethylenediphosphonic (IFCS-OEDPA-I), citric (IFCS-CA-I), and malic (IFCS-MA-I) acids were used. Azolithine (Az), lakmoid (LA), methyl orange (MO), methyl red (MR), Tropeolin OOO (TrOOO), Congo red (CoR), bromocresol green (BCG), broxylenol blue (BXB), bromophenol blue (BPB), bromophenol red (BPR), thymol blue (TB), xylenol orange (XO), and phenol red (PR) were used as acid-base indicators. The specificity of the changes in the colorimetric functions of IFCS-I during the absorption of NH3 by them was revealed. It was found that the color of the initial IFCS-I samples significantly depended not only on the structure of Ind, but also on the nature of the polybasic hydroxy acid being part of them. The colors of the samples based only on OEDPA (Ind = CoR, BCG, BPB), CA (Ind = CoR, TrOOO, BCG, BPB, BPR, XO) and some MA (TrOOO, BCG) are similar to the colors of aqueous solutions of Brönsted acids. The difference in the colors of the other samples from the colors of strong acid aqueous solutions with the same Ind is apparently due to specific interactions between hydroxy acid anions and neutral dye forms. During “response” to NH3 only some IFCS-I samples based on OEDPA (Ind: MO, TrOOO, Az and BPR), CA (Ind: CoR, MR, MO, TrOOO, BXB, BPR, TB, PR) and MA (Ind: LA, MR, MO, Az, BXB, XO, TB, PR) are discolored in contrast to the behavior of SO2 indicator chemisorbents.

Sensitive and rapid spectrophotometric methods for sertraline monitoring in pharmaceutical formulations


 
 
 
 Purpose: To develop simple, rapid, and selective spectrophotometric methods for the assay of sertraline in a pharmaceutical formulation.
 Method: These methods depend on the formation of colored ion-pair complexes between the drug and five different reagents; methyl blue (MB), bromophenol red (BPR), methyl green (MG), phenol red (PR), and methyl orange (MO) in B-R buffer solutions of pH ranging from 2.0 – 8.0. The colored products were measured at 668, 747, 647, 717, and 553 nm, respectively.
 Results: The calibration graphs were linear over the concentration range of 2 – 18 μg/mL for MB and BPR, and 2 – 16 μg/mL for MG, PR, and MO. In all cases, the reaction stoichiometry was 1:1. The proposed methods were successfully applied to solid-dose pharmaceutical preparations (tablets). Excipients in the commercial formulation did not interfere with the analysis.
 Conclusion: The investigated methods can be recommended for routine analysis and quality control where cost-effectiveness, high specificity of the analytical technique, and time are of great importance.
 
 
 

Characterization and application of ceramic membranes prepared from Algerian kaolin

Abstract In this study, a new ceramic membrane type was used for the filtration of colored water. The membrane was prepared from local Algerian kaolin KT2 of Milia-type. The choice of this raw material was dictated by its natural abundance, to form the macroporous support prepared by the slip casting technique. A functional thin film layer (with a pore size of about 0.2 μm) produced by the sol-gel method was deposited on the support to reduce the porosity. A detailed study was conducted because of the importance of this layer and the improvement which brought to the filtration process. Ceramic membranes were tested for the removal of bromophenol red (BR) under a filtration pressure of 3 bar and a duration of 2 h of treatment. The results revealed a rejection rate of 100% for BR, especially after the addition of the inorganic layer. The material was characterized by DTA, TGA, XRD and SEM. The retention and the permeability of BR were also studied.

Adsorption of Bromo Phenol Red Dye from Aqueous Solution by Iraqi Bentonite Clay

This studies deals with investigated the potential of a Iraqi bentonite clay for the adsorption of bromo phenol red dye from contaminated water. Impulse adsorption experiments were performed. The contact time influence of initial dye concentration, temperature, pH, ionic strength, partical size adsorbent and adsorbent dosage on bromo phenol red adsorption are investigated in a series of batch adsorption experiments. Adsorption equilibrium data were analyzed and described by the Freundlich, Langmuir and temkin isotherms equations. Thermodynamic parameters inclusive the Gibbs free energy (∆G•), enthalpy (∆H•), and entropy (∆S•), were also calculated. These parameters specified that adsorption of bromo phenol red onto bentonite was functional, more spontaneous and endothermic with increase of temperatures from 298.15 to 313.15 K.

Effect of calcination temperature for capability of MFe 2 O 4 (M = Co, Ni and Zn) ferrite spinel for adsorption of bromophenol red

Abstract MFe2O4 (M = Co, Ni and Zn) ferrite spinels were prepared and calcinated at 100, 200 and 300 °C. The ferrite spinels were characterized by FTIR, XRD, SEM and TEM. The CoFe2O4, ZnFe2O4 and NiFe2O4 ferrites calcinated at 300 °C had particles size of 40, 32 and 24 nm, respectively. The adsorption of bromo phenol red (BPR) by ferrite spinels was studied. The results showed that adsorption capability of nano particles was as follows: ZnFe2O4

Palladium, silver, and zinc oxide nanoparticles loaded on activated carbon as adsorbent for removal of bromophenol red from aqueous solution

The adsorption of bromophenol red (BPR) onto three adsorbents including palladium, silver and zinc oxide nanoparticles loaded on activated carbon (Pd-NP-AC, Ag-NP-AC and ZnO-NP-AC) in a batch system has been studied and the influence of various parameters has been optimized. The influence of time on removal of BPR on all adsorbent was investigated and experimental data were analyzed by four kinetic models including pseudo first and second-order, Elovich and the intraparticle diffusion equations. Following fitting the experimental data to these models, the respective parameters of each model such as rate constants, equilibrium adsorption capacities and correlation coefficients for each model were investigated and based on well known criterion their applicability was judged. It was seen that the adsorption of BPR onto all adsorbents sufficiently described by the pseudo second-order equation in addition to interparticle diffusion model. The adsorption of BPR on all adsorbent was investigated at various concentration of dye and the experimental equilibrium data were analyzed and fitted to the Langmuir, Freundlich, Tempkin, Dubinin, and Radushkevich equations. A single stage in batch process was efficient and suitable for all adsorbents using the Langmuir isotherm with maximum adsorption of 143mgg−1 for Pd-NP-AC, 250mgg−1 for Ag-NP-AC and 200mgg−1 for ZnO-NR-AC. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° for Pd-NP-AC adsorbent were calculated.

Red seaweed enzyme‐catalyzed bromination of bromophenol red: An inquiry‐based kinetics laboratory experiment for undergraduates

Haloperoxidase enzymes are of interest for basic and applied bioscientists because of their increasing importance in pharmaceutical industry and environmental cleanups. In a guided inquiry-based laboratory experiment for life-science, agricultural science, and health science undergraduates, the bromoperoxidase from a red seaweed was used to brominate bromophenol red, a novel starting substrate. Substrate and enzyme concentration dependence of this enzyme-catalyzed reaction as followed colorimetrically yielded initial rates of reaction that the students compared with those of their peers. The students worked as collaborative groups partially designing their own experiments and carrying them out. In performing the laboratory experiment, they were minimally guided by the instructor and teaching assistants. To engage the students before the laboratory, a short activity involving the enzyme-induced color change was carried out. At the end of the laboratory session, student groups discussed their results in front of the class and reached their own conclusions. Most students had better understanding of important concepts in enzyme kinetics and showed good attitude toward the overall student-centered laboratory exercise.

Use of Bromophenol Red–EDTA system for generation of electricity in a photogalvanic cell

Bromophenol Red is used as a photosensitizer in a photogalvanic cell for solar energy conversion. EDTA was used as an electron donor. The photopotential and photocurrent generated by the cell are 581.0 mV and 45.0 μA, respectively. The effects of various operating parameters, e.g. pH, light intensity, diffusion length, reductant concentration, dye concentration, on the electrical output of the cell is examined. The current–voltage ( i– V) characteristics of the cell are also observed and a tentative mechanism for the generation of the photocurrent is proposed. The performance of the cell is determined in the dark at its power point.

Computer estimation of dissociation constants. Part V. Regression analysis of extended Debye-Hueckel law

Nonlinear regression program DHMINOPT has been used for an analysis of a set of values expressing the dependence of mixed dissociation constant on ionic strength according to the extended Debye-Hueckel law. Efficiency of program has been examined on simulated data loaded with generated random errors. Goodness-of-fit brings various regression diagnostics enabling to prove a reliability of a regression process and parameter estimates. For five selected sulphonephtalein indicators, i.e. Bromocresol Green, Bromophenol Red, Bromocresol Purple, Bromothymol Blue and Phenol Red, the thermodynamic dissociation constant has been determined at 25°C together with the ion-size parameter and the salting-out coefficient.

Additional binding sites in lysozyme. X-ray analysis of lysozyme complexes with bromophenol red and bromophenol blue.

The binding sites in hen egg-white lysozyme for neutral bromophenol red (BPR) and ionized bromophenol blue (BPB) have been characterized at 2 A resolution. In either case, the dye-bound enzyme is active against the polysaccharide, but not against the cell wall. Both binding sites are outside, but close to, the hexasaccharide binding cleft in the enzyme. The binding site of BPR made up of Arg5, Lys33, Phe34, Asn37, Phe38, Ala122, Trp123 and possibly Arg125, is close to subsite F while that of BPB made up of Tyr20, Arg21, Asn93, Lys96, Lys97 and Ser100, is close to subsites A and B. The binding sites of the neutral dye and the ionized dye are thus spatially far apart. The peptide component of the bacterial cell wall probably interacts with these cells during enzyme action. Such interactions are perhaps necessary for appropriately positioning the enzyme molecule on the bacterial cell wall.

Screening for a “new” enzyme in nature: Haloperoxidase production by Death Valley dematiaceous hyphomycetes

Haloperoxidases are enzymes that have the ability to halogenate a broad range of substrates [10]. To find a biologically produced haloperoxidase that could function at a pH greater than 3.0 and at a temperature greater than 19°C, dematiaceous hyphomycetes were isolated from the Death Valley desert and screened for their ability to produce such an enzyme. A qualitative assay using bromophenol red was employed in situ over a 12-day fermentation period. Several dematiaceous hyphomycetes, such asDreschlera haloides andUlocladium chartarum, produced haloperoxidases that were active in broth culture at 19, 25, and 34°C at pH 7.0 and 8.0.

X-ray characterisation of an additional binding site in lysozyme

Bromophenol red (BPR) binds to lysozyme and inhibits its activity against bacterial cell walls, but not against the polysaccharide component of peptidoglycan. The binding site of BPR in the enzyme has been characterised by X-ray analysis of the complex at 5.5Å resolution. The new binding site, which is outside the cleft close to subsite F, is presumably involved in interactions with the peptide component of peptidoglycan, in the action of lysozyme against bacterial cell walls.

ChemInform Abstract: ELECTROREDUCTION OF PHENOL RED, CHLOROPHENOL RED AND BROMOPHENOL RED IN BUFFER SOLUTIONS AT DME

Chemischer InformationsdienstVolume 12, Issue 24 Article ChemInform Abstract: ELECTROREDUCTION OF PHENOL RED, CHLOROPHENOL RED AND BROMOPHENOL RED IN BUFFER SOLUTIONS AT DME M. M. GHONEIM, M. M. GHONEIMSearch for more papers by this authorR. M. ISSA, R. M. ISSASearch for more papers by this authorR. A. MAHMOUD, R. A. MAHMOUDSearch for more papers by this author M. M. GHONEIM, M. M. GHONEIMSearch for more papers by this authorR. M. ISSA, R. M. ISSASearch for more papers by this authorR. A. MAHMOUD, R. A. MAHMOUDSearch for more papers by this author First published: June 16, 1981 https://doi.org/10.1002/chin.198124094AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume12, Issue24June 16, 1981 RelatedInformation

Bromophenol red as a probe of lysozyme-active site environment: a temperature-jump study.

AbstractSpectrophotometric techniques have been employed to study the binding of bromophenol red (BPR) to hen egg white lysozyme and the consequent inhibition of enzyme activity. Experimental evidence is given from the dye binding studies in the presence of hexasaccharide and from the studies on activity that BPR binds at a site outside the proposed cleft region (A–F) in such a way that it inhibits the lytic activity towards cell walls but does not inhibit the activity towards hexasaccharide. These observations are consistent with the kinetics of binding [studied using temperature‐jump (T‐jump)] in the presence of Co++ or chitotriose in large concentrations and the experiments with acetylated lysozyme which suggest that the binding site of BPR is closer to a lysine residue near the cleft. It is suggested that the binding site of BPR could be important in positioning the peptide segment of the cell walls, which are cleaved in the cleft.Evidence for the statement that this binding takes place at least by a two‐step process, in which the bimolecular step is followed by a slower monomolecular step, is given from the observations of two types of 1:1 complexes at 24°C in equilibrium studies and from the concentration dependence of the relaxation observed at 605 nm in the T‐jump experiments. The binding process is examined by analyzing the T‐jump data obtained between 18 and 33°C in the pH range 5.2–9.2 and ionic strength 0.01–01. The ionic strength and pH dependences of the equilibrium constant associated with the bimolecular step k2/k1 and the forward rate constant associated with monomolecular step k3 have been given as evidence for the suggestion that a Coulombic interaction is involved in the first step of binding. However, the final state of binding is hydrophobic in nature. The enthalpy of activation ΔH and the entropy of activation ΔS associated with kf[= k3(k1/k2)] showed compensation behavior with pH variation, with maxima around pH ∼ 7.5 in H2O. This has been interpreted as a maximal disordering of water structure in a region of the enzyme at this pH during the monomolecular step. However, the binding of chitotriose or Co++ in the cleft reduces the ΔH and ΔS associated with the monomolecular step of BPR binding, probably by disordering the structured water during their binding in the cleft. The differences in the kinetic parameters obtained in H2O and in D2O probably arise due to subtle differences in the conformation of the enzyme in the two solvents and apart from isotope effects.The correlation between the pH (or pD) dependence of the “intrinsic activity” towards cell walls and ΔH or ΔS indicates that ordered water structure could be playing a role in controlling the catalytic activity. It is also suggested that this factor is associated with the rate constant k3s of the monomolecular step leading to the formation of the final bound state of the substrate in cell lysis, which is also a factor controlling kcat.

ChemInform Abstract: INDICATORS IN BENZENE IN THE PRESENCE OF DODECYLAMMONIUM PROPIONATE

Monomeric dodecylammonium propionate undergoes hydrogen bonded ion-pair formation with 2,4–, 2,5– and 2,6-dinitrophenol and trinitrophenol in dry benzene. The association constants for the formation of these ion pairs parallel those formed between dinitrophenols and triethylamine in the same solvent. Addition of acid to aggregated dodecylammonium proprionate in benzene containing 0.55 mol dm–3 water results in the neutralization of the propionate ion. Determination of the ratio of propionate ion to propionic acid allowed the calculation of the apparent dissociation constants, pKappa values, for 2,4–, 2,5–, 2,6-dinitrophenol, 2,4,6-trinitrophenol, Bromophenol Blue Bromophenol Red, Malachite Green and vitamin B12a in 0.55 mol dm–3 water solubilized by 0.10 mol dm–3 dodecylammonium propionate in benzene. Values of pKappa for these indicators closely resemble the corresponding pKa values in water.

Indicators in benzene in the presence of dodecylammonium propionate

Monomeric dodecylammonium propionate undergoes hydrogen bonded ion-pair formation with 2,4–, 2,5– and 2,6-dinitrophenol and trinitrophenol in dry benzene. The association constants for the formation of these ion pairs parallel those formed between dinitrophenols and triethylamine in the same solvent. Addition of acid to aggregated dodecylammonium proprionate in benzene containing 0.55 mol dm–3 water results in the neutralization of the propionate ion. Determination of the ratio of propionate ion to propionic acid allowed the calculation of the apparent dissociation constants, pKappa values, for 2,4–, 2,5–, 2,6-dinitrophenol, 2,4,6-trinitrophenol, Bromophenol Blue Bromophenol Red, Malachite Green and vitamin B12a in 0.55 mol dm–3 water solubilized by 0.10 mol dm–3 dodecylammonium propionate in benzene. Values of pKappa for these indicators closely resemble the corresponding pKa values in water.

Microdetermination of the arsonic group in organic compounds by titration in non-aqueous solvents

The arsonic group in organic compounds is determined titrimetrically in dimethylformamide using sodium methoxide. Bromophenol red is recommended as a visual indicator. One mole of the titrant is cosumed per mole of the compound. Phenolic hydroxyl group does not interfere. The precision is ± 0.2 %. Dimethylformamide with phenolphthalein or benzene with thymol blue may also be used but hydroxyl group if present interfere.