scholarly journals AMINOMETHANSULFONIC AND ALKYLAMINOMETHANSULFONIC BUFFER SYSTEMS

2019 ◽  
Vol 85 (9) ◽  
pp. 3-16
Author(s):  
Ruslan Khoma ◽  
Alim Ennan ◽  
Aleksandr Chebotarev ◽  
Sergey Vodzinskii
Keyword(s):  
Chemical Analysis ◽  
Electron Donor ◽  
Concentration Ratio ◽  
Buffer Capacity ◽  
Water Systems ◽  
Acid Base ◽  
Buffer Action ◽  
Ph Values ◽  
Biochemical Studies ◽  
Medium Acidity

The investigations of acid-base interactions in aminomethanesulfonic acid (AMSA)–potassium aminomethanesulfonate–water and alkylaminomethanesulfonic acid–potassium alkylaminomethane-sulfonate–water systems, where alkyl are methyl (MeAMSA), N-(2-hydroxyethyl) (HEAMSA), n-propyl (n-PrAMSA), n-butyl (n-BuAMSA), tert-butyl (t-BuAMSA), n-heptyl (n-HpAMSA) and benzyl (BzAMSA) were performed in temperature range 293–313 К. Buffer action pH limits were determined and the buffer capacity of these systems was estimated.Based on the evaluation of buffer action pH limits of aminomethansulfonic acids, it has been found that with the help of n-PrAMSA and n-BuAMSA, it was possible to maintain the medium acidity in the range of physiological pH values throughout the range of investigated temperatures.As the temperature rises, the pH of the lower buffer limit increases for AMSA and n-BuAMSA systems, while for HEAMSA, t-BuAMSA, n-HpA-MSA and BzAMSA decreases. The value of the pH of the upper buffer threshold for all tested systems decreases during their heating. With the increase of the electron-donor properties of the N-substituent in the AMSA–MeAMSA–HEAMSA–t-BuAMSA series, the value of their electronegativity decreases to result in lowering of the pH values of the lower buf-fering action limit of these systems. For the more lipophilic N-substituents (n-C4H9, n-C7H15 and C6H5CH2), this regularity is not typical.It has been established that with increasing the CYAMSK/CYAMSA concentration ratio, the buffer capacity of YNHCH2SO3H–YNHCH2SO3K–H2O systems with hydrophilic aminomethansulfonic acids (Y = H, CH3 and HOCH2CH2) increases. For systems with lipophilic n-PrAMSA and t-BuAMSA, their buffer capacity doesn’t change at 0.4 ≤ QKOH/QYAMSA ≤ 1.0.The obtained data on the buffer capacity of the investigated systems is recommended for use in chemical analysis, microbiological and biochemical studies.

scholarly journals ACID-BASE PROPERTIES OF -UNSATURATED KETONES OBTAINED FROM REACTION OF 5-FORMYL-8-HYDROXYQUINOLINE WITH P-SUBSTITUTED ACETOPHENONES

2019 ◽  
Vol 16 (31) ◽  
pp. 755-764
Author(s):  
Roberto FERNANDEZ-MAESTRE ◽  
Alonso J MARRUGO-GONZÁLEZ
Keyword(s):  
Electron Donor ◽  
Opposite Effect ◽  
Dissociation Constants ◽  
Phenyl Group ◽  
Hydroxyl Group ◽  
Ultraviolet Spectroscopy ◽  
Acid Base ◽  
Unsaturated Ketones ◽  
Ph Values ◽  
Phenyl Fragment

Chalcones (α,β-unsaturated ketones) containing aromatic or heterocyclic radicals are highly reactive, allowing the synthesis of novel organic compounds. In this study, the dissociation constants (pKa) of seven chalcones derived from 8-hydroxyquinoline were determined and the influence on dissociation of substituents in the phenyl group (-CH3, -OCH3, -N(CH3)2, -Cl, -Br, and -NO2) was analysed. pKa values are important because they determine the pH at which ligands are fully deprotonated -when they show their maximum chelating properties- and determine the ligands interactions at different pH values. The chalcones’ pKa’s were calculated by visible ultraviolet spectroscopy in a water-ethanol (1:1) mixture using the Henderson-Hasselbach equation. It was shown that the 8-hydroxyquinolinic fragment has a large electron donor effect on the π system of the chalcones. The introduction of substituents (R) in the phenyl fragment of the chalcones slightly affected the dissociation of the hydroxyl group and the protonation of the nitrogen in the hydroxyquinoline fragment. The acceptor substituents (Cl, Br, NO2) increased the polarity of OH- and its acidity. Nitrogen protonation decreased electron donor properties of this fragment, and deprotonation of the hydroxyl caused the opposite effect. Substituents introduction in the phenyl fragment slightly affected hydroxyl group dissociation and nitrogen protonation.

scholarly journals BUFFER SYSTEMS BASED ON AMINOMETANESULPHONATE AND MONOETHANOLAMMONIUM N-ALKYLAMINOMETHANESULPHONATES

2021 ◽  
Vol 26 (2(78)) ◽  
pp. 22-31
Author(s):  
R.E. Khoma ◽  
А. А-А. Ennan ◽  
T. S. Bienkovska ◽  
L. T. Osadchiy ◽  
E. L. Roy
Keyword(s):  
Buffer Capacity ◽  
Acid Base ◽  
Ph Buffering ◽  
Ph Values ◽  
Titration Curves ◽  
Upper Limit ◽  
Empirical Function ◽  
Ionic Associates ◽  
Aminomethanesulfonic Acids ◽  
Acidic Region

The limits of the pH buffering action (pHbuff) of YNHCH2SO3H – NH2CH2CH2OH –H2O (Y = H, CH3, HOCH2CH2, t-С4H9 and C6H5CH2) were determined and their buffer capacity (p) for monoethanolamine (MEA) was estimated in the temperature range 293–313 K. For systems with aminomethanesulfonic acid (AMSA), its N‑methyl, N‑hydroxyethyl (HEAMSA) and N‑benzyl (BzAMSA) derivatives, an increase in temperature leads to a decrease in the pH values of the lower limit of the buffering action of their solutions with monoethanolamine; in the case of N‑tert-butylaminomethanesulfonic acid (t-BuAMSA) – to an increase in the specified characteristic. An increase in temperature for systems with the most hydrophobic t-BuAMSA and BzAMSA (in comparison with other studied aminomethanesulfonic acids) leads to a decrease in the pH values of the upper limit of the buffer action. A decrease in the YNHCH2SO3H and NH2CH2CH2OH concentration leads to a shift in the boundaries of the pH of the buffering action to a more acidic region. The nature of the influence of the empirical function, combining their acid-base properties and lipophilicity (рKа + lgPow), on the concentration dependence of the buffer capacity according to MEA was revealed. It is shown that the buffering effect of the studied systems is due to the presence, in addition to the systems N‑alkylammoniummethanesulfonate – N‑alkylaminomethanesulfonate and 2-hydroxyethylammonium – monoethanolamine, ionic associates (pairs and triples). The position of the extrema on the graphical π=f(CMEA)/QYAMSA) dependencies for systems with hydrophilic AMSA and HEAMSA coincides with the position of the first minima on the differential titration curves dpH/dV = f(CMEA)/QYAMSA). Substitution of MEA to potassium aminomethanesulfonate leads to a shift in the pH buffering action to a more acidic region and increases the buffer capacity of the resulting systems.

scholarly journals Acidity Study of Donor-Acceptor Complexes of Boric Acid with Polyols for Oil Displacing Compositions

2019 ◽  
pp. 364-373
Author(s):  
Vladimir A. Kuvshinov ◽  
Lyubov K. Altunina ◽  
Lyubov A. Stasieva ◽  
Ivan V. Kuvshinov
Keyword(s):  
Electrical Conductivity ◽  
Boric Acid ◽  
Buffer Capacity ◽  
Experimental Studies ◽  
Acid Base ◽  
Buffer Action ◽  
Donor Acceptor

The results of theoretical and experimental studies of the acidity of donor-acceptor complexes of boric acid with polyols – glycerol and sorbitol, which were used in the development of oil-displacing compositions, are presented. A model of donor-acceptor acid-base equilibria in coordinating polyol solvents has been created, due to which the constants of polyolboric acids formation and ionization were determined by pH-meter and electrical conductivity methods. The obtained constant values were used to calculate the compositions buffer capacity. Due to the using a mixture of polyolboric acids in the compositions at various ratios it was possible to regulate the range of the buffer action

Synthesis, Characterization and Thermal studies of Novel Organomercury Driven from Sulfa Drugs Part 1

2011 ◽  
Vol 7 (2) ◽  
pp. 1338-1347
Author(s):  
Tarek Ali Fahad ◽  
Shaker.A.N. AL-Jadaan
Keyword(s):  
Thermal Decomposition ◽  
Thermal Behavior ◽  
1H Nmr ◽  
Elemental Analysis ◽  
Thermal Studies ◽  
Spectroscopic Techniques ◽  
Sulfa Drugs ◽  
Acid Base ◽  
Ph Values ◽  
Multi Stage

Two new heterocyclic Organmercury compounds   were prepared from the reaction of Sulfamethaxazole and Sulfadiazine with 4-acetaminophenol as a coupler and separated as solids with characteristic colors. these compounds were characterized by F.T.IR-spectroscopy 1H-NMR , Micro-elemental Analysis and UV-Vis spectroscopic techniques . The work involves a study of acid – base properties compounds at different pH values, the ionization and protonation constants were calculated. The thermal behavior of these two compounds   were investigated on the basis of thermogravimetric (TGA) and differential thermogravimetric (DTG) analyses, Thermal decomposition of these compounds is multi-stage processes.

THE CONTRIBUTION OF LACTATE AND PHOSPHATE ANIONS TO THE BUFFER PROPERTIES OF TISSUE HOMOGENATES OF BREAST ADENOCARCINOMA

2019 ◽  
Vol 65 (5) ◽  
pp. 684-690
Author(s):  
Margarita Barsukova ◽  
Yekaterina Khomutova ◽  
Yevgeniy Khomutov
Keyword(s):  
Mammary Gland ◽  
Buffer Capacity ◽  
Tumor Tissue ◽  
Mammary Adenocarcinoma ◽  
Breast Adenocarcinoma ◽  
Acid Base ◽  
Adjacent Tissue ◽  
Tumor Tissues ◽  
Tissue Homogenates ◽  
Phosphate Anions

The article discusses the role of conjugated lactic acid/ lactate anion (LacH/Lac-) and dihydrogenphosphate anion/ hydrogenphosphate anion (H2PO4-/HPO42-) pairs in the formation of the buffer properties of tissue as a factor determining pH. The buffer properties of homogenates of the tissue of adenocarcinoma of the mammary gland and the adjacent tissue were quantitatively characterized by the buffer capacity which was determined by potentiometric titration. The concentrations of acid anions were determined spectrophotometrically. The material was biopsy specimens of mammary gland adenocarcinoma (T1-4, N0-1, M0) and adjacent tissue of 22 patients aged from 33 to 75 years. It was found that the buffer capacity of tumors is in 2.5 times higher than in normal tissue. It was established that for the tumor tissue, the buffer capacity of the LacH/Lac- system is in 3 times higher, and the buffer capacity of the H2PO4-/HPO42-system is in 2.5 times greater than for normal untransformed tissue. Concentrations of lactate anions (1,93 ± 0,50 vs 0,57 ± 0,22; p <0.001) and phosphate anions (2,54 ± 0,39 vs 0,70 ± 0,19; p <0,001) in homogenates of the tumor tissue were significantly higher in tumor tissue in comparison with the adjacent tissue. A strong correlation was found between the concentration of phosphate anions and the buffer capacity for tumor tissue (r = 0,857; p = 0,002) and for adjacent tissue (r = 0,917; p <0,001). The correlation between the concentration of lactate anions and the buffer capacity for tumor tissues can be estimated as average (r = 0,626; p = 0,053), while it is absent for the adjacent tissue (r = 0,494; p = 0,147). The results suggest that the acid-base properties of homogenates of mammary adenocarcinoma tissues are determined by two buffer systems: LacH/Lac- and H2PO4-/HPO42-, while the intracellular acid-base homeostasis of non-transformed tissues is mainly determined by the H2PO4-/HPO42- system.

scholarly journals Immobilization of Cd, Zn, and Pb from Soil Treated by Limestone with Variation of pH Using a Column Test

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Sung-Wook Yun ◽  
Chan Yu
Keyword(s):  
South Korea ◽  
Water Systems ◽  
Metal Mobility ◽  
Acid Solutions ◽  
Test Results ◽  
Column Test ◽  
Acidic Solutions ◽  
Ph Values ◽  
Metal Mines ◽  
Site Restoration

Decades of mining in South Korea have resulted in the contamination of large amounts of soil by metals. The most feasible approach to site restoration requires the use of a stabilization agent to reduce metal mobility. This study examined the leaching characteristics of limestone used as a stabilization agent when subjected to solutions of differing pH. In a laboratory-scale column test, solutions with pH values of 3.5, 4.6, and 5.6, representing acidic to nonacidic rainfall, were applied to soil mixed with limestone. Test results indicate that metal components can be released with the addition of acidic solutions, even if the soil is highly alkaline. Cd and Zn, in particular, exhibited abrupt or continuous leaching when exposed to acid solutions, indicating the potential for contamination of water systems as metal-laden soils are exposed to the slightly acidic rainfall typical of South Korea. Treatment using stabilization agents such as limestone may reduce leaching of metals from the contaminated soil. Stabilizing metal-contaminated farmland is an economical and feasible way to reduce pollutants around abandoned metal mines.

Variable charges of a red soil from different depths: Acid-base buffer capacity and surface complexation model

2018 ◽  
Vol 159 ◽  
pp. 107-115 ◽  
Author(s):  
Ying Wang ◽  
Pengfei Cheng ◽  
Fangbai Li ◽  
Tongxu Liu ◽  
Kuan Cheng ◽  
...  
Keyword(s):  
Buffer Capacity ◽  
Surface Complexation ◽  
Red Soil ◽  
Acid Base ◽  
Surface Complexation Model ◽  
Different Depths

scholarly journals Remaining phosphorus and sodium fluoride pH in soils with different clay contents and clay mineralogies

2004 ◽  
Vol 39 (3) ◽  
pp. 241-246 ◽  
Author(s):  
Marcelo Eduardo Alves ◽  
Arquimedes Lavorenti
Keyword(s):  
Buffer Capacity ◽  
Ammonium Oxalate ◽  
Clay Mineralogy ◽  
Clay Content ◽  
Response Curves ◽  
Solution Ph ◽  
Ph Values ◽  
Soil Clay ◽  
Soil Clay Content ◽  
Discriminatory Capacity

The remaining phosphorus (Prem) has been used for estimating the phosphorus buffer capacity (PBC) of soils of some Brazilian regions. Furthermore, the remaining phosphorus can also be used for estimating P, S and Zn soil critical levels determined with PBC-sensible extractants and for defining P and S levels to be used not only in P and S adsorption studies but also for the establishment of P and S response curves. The objective of this work was to evaluate the effects of soil clay content and clay mineralogy on Prem and its relationship with pH values measured in saturated NaF solution (pH NaF). Ammonium-oxalate-extractable aluminum exerts the major impacts on both Prem and pH NaF, which, in turn, are less dependent on soil clay content. Although Prem and pH NaF have consistent correlation, the former has a soil-PBC discriminatory capacity much greater than pH NaF.

Electron Donating, Acid-Base and Catalytic Properties of Perovskite-Type Mixed Oxides of Rare Earths

1995 ◽  
Vol 60 (6) ◽  
pp. 977-982
Author(s):  
S. Sugunan ◽  
V. Meera
Keyword(s):  
Catalytic Activity ◽  
Electron Donor ◽  
Rare Earths ◽  
Electron Affinity ◽  
Mixed Oxides ◽  
Catalytic Properties ◽  
Surface Acidity ◽  
Electron Acceptors ◽  
Acid Base ◽  
Perovskite Type

The electron donor properties of perovskite-type mixed oxides (LaFeO3, PrFeO3, SmFeO3, LaCoO3, PrCoO3, SmCoO3, LaNiO3, PrNiO3 and SmNiO3) were studied based on the adsorption of electron acceptors exhibiting different electron affinity viz. 7,7,8,8-tetracyanoquinodimethane, 2,3,5,6-tetrachloro-1,4-benzoquinone, p-dinitrobenzene, and m-dinitrobenzene. The surface acidity/basicity of the oxides was determined using a set of Hammett indicators. The data were correlated with the catalytic activity of the oxides for the reduction of cyclohexanone with 2-propanol.

scholarly journals The pH measurement with glass electrode in an electromagnetic field

2016 ◽  
Vol 81 (12) ◽  
pp. 1407-1414 ◽  
Author(s):  
Dragan Veselinovic ◽  
Zoran Velikic
Keyword(s):  
Electromagnetic Field ◽  
Buffer Capacity ◽  
Extreme Values ◽  
Ph Value ◽  
Radiation Power ◽  
Glass Electrode ◽  
Frequency Interval ◽  
Buffer Solutions ◽  
Ph Values ◽  
Glass Electrodes

Measurements of pH values of buffer solutions (pH 4.0, 7.0 and 10.0) and distilled water have been performed with a glass electrode in electromagnetic field at the frequency interval of 10 MHz to 200 MHz and the output power of dispersed and reflected electromagnetic radiation of 0.01 W to 3 W. In all the cases, there occurred a reduction of pH values, i.e. a "recorded pH value" was obtained. The reduction appears within the applied frequency interval reaching extreme values at specific frequencies. The reduction of the pH values increases with the radiation power and depend of the solution buffer capacity. The effect of electromagnetic field on pH value change is exerted dominantly through the influence on glass electrodes.

Sign in / Sign up

Export Citation Format

Share Document