Potentiometric Titration Curves Research Articles

Determination of Antioxidant Additive and its Decomposition Products in Working Motor Fuels

Sulfur compounds are formed during the oxidation of motor oil under the influence of high temperatures, and it is quite difficult to determine the residual content of an active additive. To determine the DF-11 additive the M-10G2k oil was oxidized in a thermostat. It was established that with oxidation times of 8 and 10 hours it is only possible to determine the amount of mercaptan sulfur from the potentiometric titration curve. An algorithm and some methods of determination that make it possible to predict the wear and service life of lubricating oil are proposed for complete determination of sulfur-containing compounds in oxidized oil under working conditions.

Heat-induced gelation of mixtures of casein micelles with whey protein aggregates

Gelation of aqueous solutions of casein micelles (MC) in mixtures with fractal aggregates of whey protein isolate (WPI) has been studied first by addition of different amounts of aggregates at a fixed concentration of micelles and then by substitution of micelles with aggregates at a fixed total protein concentration. Addition of small amounts of aggregates (1–5 g/L) to suspensions of micelles (20–60 g/L) at a fixed pH led to a strong decrease of the gelation temperature (Tg) and to an increase of the elastic modulus (G′) of the mixed gels. A minimum in Tg and a maximum in G′ as a function of the WPI fraction were obtained in mixtures with fixed total protein concentration and fixed pH and explained by the opposing influence of increasing WPI aggregate concentration and decreasing concentration of micelles. Increasing the total protein concentration at the same WPI fraction caused a decrease of Tg and increase of G′. Decreasing the pH at the same protein composition led to a decrease of Tg but caused an increase of G′. Tg decreased sharply if a small amount of CaCl2 was added, but if more than about 30 mM of calcium was added, Tg increased again. Gelation of mixtures did not depend significantly on the size of the WPI aggregates, but if fractal aggregates were replaced by microgels, weaker gels were produced and the temperature of gelation was higher. Potentiometric titration curves showed that protonation of the micelles and of the WPI aggregates in the mixtures was independent. It is concluded that MC and WPI aggregates co-aggregate during gelation and there is a transition between gelation at a critical temperature for pure MC suspensions and gelation controlled by an activation energy for pure WPI aggregate suspensions.

Analysis of the Fibroin Solution State in Calcium Chloride/Water/Ethanol for Improved Understanding of the Regeneration Process

Shaping of fibroin protein from Bombyx mori from calcium chloride/water/ethanol solution is of high interest for the manufacturing of biocompatible structures. Potentiometric titration experiments of the dissolved state permit new insight into the solution state of fibroin as a basis for improved regeneration. Titration experiments and infrared spectroscopy of the solution state support the model of an ion-rich hydration layer and interaction of the solvent with charged and polar groups of the fibroin, rather than through formation of defined calcium complexes. The potentiometric titration curves indicate the formation of calcium complexes at pH values above 9, most probably through involvement of basic amino acids and phenolic groups of tyrosine. After regeneration by the addition of methanol, the regenerated protein was characterised by FTIR, nitrogen and calcium analysis. The analysis of supernatants for their residual protein content indicated minor losses of protein, most probably low molecular weight proteins. The results contribute to an improved understanding of the solution state as a basis for larger scale regeneration, e.g. for the coating of textile fibres with regenerated fibroin.

Multiple dissociation constants of the Intepirdine hydrochloride using regression of multiwavelength spectrophotometric pH-titration data

Spectrophotometric and potentiometric pH-titrations of the Neurotransmitter Intepirdine hydrochloride INN·HCl for three dissociation constants determination were compared. A nonlinear regression of the pH-spectra (REACTLAB, SQUAD84) and of the pH-titration curve (ESAB) determined three multiple dissociation constants. A sparingly soluble neutral molecule LH of INN·HCl was capable of protonation to form the still soluble three cations LH2+, LH32+ and LH43+ in pure water. Although the change of pH somewhat less affected changes in the chromophore, three consecutive thermodynamic dissociation constants were estimated pKTa1=5.64, pKTa2=7.31, pKTa3=8.85 at 25°C and pKTa1=5.51, pKTa2=7.15, pKTa3=8.77 at 37°C. The graph of molar absorption coefficients of variously protonated species according to wavelength shows that the spectrum of species LH2+ and LH vary in colour, while protonation of chromophore LH2+ to LH32+ and LH43+ has less influence on chromophores in Intepirdine hydrochloride molecule. As the spectral response on the chromophore in the INN·HCl molecule is not large, it was necessary to test a reliability whether it is possible to estimate the dissociation constants even from such small spectrum changes. Three multiple thermodynamic dissociation constants of 3×10−4M INN·HCl were determined by the regression analysis of potentiometric titration curves pKTa1=5.14, pKTa2=8.38, pKTa3=9.33 at 25°C and pKTa1=5.17, pKTa2=8.31, pKTa3=9.07 at 37°C. The macro-dissociation constants of INN·HCl were estimated according to the chemical structure analyzed by two pKa predictors, the MARVIN and ACD/Percepta programs. The resulting protonation scheme of INN·HCl was suggested.

Graphic image of high quality wines

The objects of the research were samples of high quality wines of various types produced by the enterprises of the Krasnodar Territory, the Rostov Region and foreign producers of different grape varieties. The method of automatic titration of acids in wines was applied by coulometric generation of the base with the recording of the results of potentiometric indication on the computer. The influence of the grape variety and the duration of aging of table wine on the appearance of the titration curves was carried out using 77 technical grades and clones of grapes (44 red grapes and 33 white grapes) from the Anapsko-Tamanskaya zone of the Krasnodar Territory from 2001 to 2016. Grapes of the studied varieties were processed under the micro nodulation conditions according to two schemes. Dry table red wines were obtained by fermentation on the mash. Dry table white wines were produced using the high quality low-oxidized wines. The experimental studies confirming the individuality of the titration curves and the absorption spectra of wine samples for specific brands have been carried out. The principal possibility was shown of using the coordinates of the titration curve of a wine sample for establishing a relationship with the grape variety and the authenticity of the production of wines with the protected geographical indication and appellation of origin. To confirm the authenticity of the wine products, it was suggested to compare the data matrix with the coordinates describing the average titration curve of a specific wine product obtained by the manufacturer with a similar matrix obtained by the controlling party under the reproducibility conditions. When the appearance of the titration curves of red wines obtained from different grape varieties was identical, it was suggested to additionally apply a matrix of data describing the absorption spectrum in the visible region. Key words : organic acids, authenticity of wines, potentiometric titration curves, spectral characteristics DOI: http://dx.doi.org/10.15826/analitika.2018.22.3.003 (Russian) O.N. Shelud`ko 1,2 , N.K. Strizhov 2 , T.I. Guguchkina 1 , T.V. Guzik 2 1 Northern-Caucasian Federal Scientific Center for Horticulture, Viticulture, Winemaking. Russian Federation, 350901, Krasnodar, 40th Anniversary of the Victory st., 39 2 Kuban State Technological University, Russian Federation, 350072, Krasnodar, Moscow st.,2

Input of different kinds of soluble pectin to cation binding properties of roots cell walls

It is widely believed that pectin are responsible for the vast majority of cation binding positions in the root cell walls. To estimate the role of particular kinds of pectin, we studied the cell wall material isolated from the roots of monocots (wheat and rye) and dicots (clover and lupine) before and after removal of different fractions of soluble pectin. Simultaneously PME activity and degree of pectin methylation were determined. From potentiometric titration curves cation exchange capacity, total surface charge and acidic strength of surface functional groups responsible for surface charging were determined. Monocots had smaller cation exchange capacity and lower pectin content than dicots. Removal of pectin induced up to 50% reduction in the cell walls surface charge. Pectin seem to have more acidic character than the other roots components that is seen from an increase in very weakly acidic groups fraction and significant decrease in the average dissociation constant of the cell walls material after pectin removal. Water soluble pectin and non-pectic soluble compounds had the dominant role in surface charging, while chelator and diluted alkali soluble pectin contributed to surface charge only at high pH's.

Overlapping pK a of the Multiprotic Hemostyptic Eltrombopag using UV–Vis Multiwavelength Spectroscopy and Potentiometry

Dissociation constants of the multiprotic hemostyptic Eltrombopag determined by pH-potentiometric and WApH-spectrophotometric titrations are compared. Hemostyptic and hemostatic Eltrombopag treats low blood platelet counts in adults with chronic immune idiopathic thrombocytopenia ITP. Eltrombopag has five protonatable sites in a pH range of 2–10, where only two pK are well separated (ΔpK > 3), while the other three are near dissociation constants of overlapping equilibria. According to the MARVIN prediction, in neutral medium Eltrombopag occurs in the slightly water soluble form LH3 that can be protonated to the soluble species $$ {\text{LH}}_{4}^{ + } $$ and $$ {\text{LH}}_{5}^{2 + } $$ The molecule LH3 can be dissociated to still difficultly soluble species $$ {\text{LH}}_{2}^{ - } $$ , $$ {\text{LH}}^{2 - } $$ and $$ {\text{L}}^{3 - } $$ . Due to the limited solubility of Eltrombopag above pH = 9.5 the protonation was studied up to pH = 10. Five dissociation constants can be reliably determined with REACTLAB and SQUAD84 leading to the same values. From a dependence on ionic strength, the thermodynamic dissociation constants were estimated at 25 °C: $$ {\text{p}}K_{{{\text{a}}1}}^{\text{T}} $$ = 2.69, $$ {\text{p}}K_{{{\text{a}}2}}^{\text{T}} $$ = 6.97, $$ {\text{p}}K_{{{\text{a}}3}}^{\text{T}} $$ = 7.13, $$ {\text{p}}K_{{{\text{a}}4}}^{\text{T}} $$ = 7.65, $$ {\text{p}}K_{{{\text{a}}5}}^{\text{T}} $$ = 8.30. At pH values above 10 and pH below 5 a very fine precipitate of Eltrombopag, forming a slight opalescence, was observed; thus measurements of the potentiometric titration curve above pH = 9 and pH below 5 were excluded from the regression analysis to estimate pK a2 = 6.59(01), pK a3 = 7.56(04), pK a4 = 8.48(59) and pK a5 = 9.29(34) at 25 °C with ESAB.

SYNTHESIS AND CHARACTERIZATION OF INDINAVIR-Cu COMPLEX

Objective: The main objective of the present work is to synthesize Cu (II) indinavir, complex.Methods: The indinavir complexes were discussed with the help of spectroscopic instrumental methods such as infrared, ultraviolet, nuclear magnetic resonance, and mass and titrimetry methods (iodometry and potentiometry). Drug and drug metal complex are screened against antimicrobial activity.Results: The spectral studies show that the metal is coordinated to the drug in a bidentate manner. The titrimetry method, i.e., iodometric titration shows that metal bind to the drug in proportion of 1:1. The potentiometric titration curves of indinavir-Cu metal complex are mostly same which proves that the metal which might be present in the complex do not affect the titration curves. The result shows that the drug metal complex has enhanced inhibitory activity than drug under identical conditions in concentration ranges of 12.5 μg/ml in Staph and Bacillus species whereas in disc diffusion procedure zone of inhibition is 13 mm and 18 mm in Staph and Bacillus species.Conclusion: Indinavir-Cu complex had been synthesized and characterized by spectral techniques which shows enhanced microbial activity than drug.

The role of cell walls and pectins in cation exchange and surface area of plant roots

We aimed to assess role of cell walls in formation of cation exchange capacity, surface charge, surface acidity, specific surface, water adsorption energy and surface charge density of plant roots, and to find the input of the cell wall pectins to the above properties. Whole roots, isolated cell walls and the residue after the extraction of pectins from the cell walls of two Apiaceae L. species (celeriac and parsnip) were studied using potentiometric titration curves and water vapor adsorption – desorption isotherms.Total amount of surface charge, as well as the cation exchange capacity were markedly higher in roots than in their cell walls, suggesting large contribution of other cell organelles to the binding of cations by the whole root cells. Significantly lower charge of the residues after removal of pectins was noted indicating that pectins play the most important role in surface charge formation of cell walls. The specific surface was similar for all of the studied materials. For the separated cell walls it was around 10% smaller than of the whole roots, and it increased slightly after the removal of pectins. The surface charge density and water vapor adsorption energy were the highest for the whole roots and the lowest for the cell walls residues after removal of pectins.The results indicate that the cell walls and plasma membranes are jointly involved in root ion exchange and surface characteristics and their contribution depends upon the plant species.

Spectrofluorimetric and Potentiometric Determination of Acidity Constants of 4-(4'-Acetyloxy-3'-Methoxybenzylidene)-5-Oxazolone Derivatives.

4-(4'-acetyloxy-3'-methoxybenzylidene)-5-oxazolone fluorescent molecules bearing four different aryl groups attached to the 2-position of 5-oxazolone ring have been investigated by spectrophotometric and potentiometric techniques in solution media. The acidity constants (pKa) of the fluorescent molecules were precisely determined in acetone, acetonitrile, dimethylformamide and in 1:1 mixture of toluene-isopropanol. The studied derivatives were titrated with tetrabutylammonium hydroxide and non-aqueous perchloric acid by scanning the basic and acidic region of the pH scale. A computerizable derivative method was used in order to descript precisely the end point and pKa values. The molecules investigated performed well-shaped and stoichiometric potentiometric titration curves.

Stable suspensions of doped ceria nanopowders for electrophoretic deposition of coatings for solid oxide fuel cells

We have studied nonaqueous suspensions of Ce0.8Sm0.2O1.9 (CSO), Ce0.8Gd0.2O1.9 (CGO), and Се0.8(Sm0.75Sr0.2Ba0.05)0.2O2–δ (CSSBO) nanopowders produced by laser evaporation of a target. The nanoparticles were nearly spherical in shape and their average diameter was 9, 7, and 15 nm, respectively. Using ultrasonic processing, we obtained stable nanopowder suspensions in an isopropanol + acetylacetone mixed medium, investigated their particle size composition, evaluated their zeta potential as a function of pH, and obtained potentiometric titration curves. The starting nanopowder suspensions have been shown to be weakly acidic and have a rather high initial zeta potential. During titration of the nanopowder suspensions with 0.17 N KOH in isopropanol, no isoelectric point was observed. The maximum positive values of the zeta potential, favorable for electrophoretic deposition (EPD), were reached in weakly acidic media in the pH range 4–6. Using EPD, we obtained a coating from a stable self-stabilized CSSBO suspension (ζ = +31 mV, pH 4.0), which was then sintered in air at a temperature of 1400°C. Our results demonstrate that the starting nonaqueous suspensions of the CSO, CGO, and CSSBO nanopowders suit well for producing gas-tight, homogeneous solid oxide fuel cell coatings by EPD.

Analysis of the sorption properties of different soils using water vapour adsorption and potentiometric titration methods

Abstract Parameters of specific surface area as well as surface charge were used to determine and compare sorption properties of soils with different physicochemical characteristics. The gravimetric method was used to obtain water vapour isotherms and then specific surface areas, whereas surface charge was estimated from potentiometric titration curves. The specific surface area varied from 12.55 to 132.69 m2 g−1 for Haplic Cambisol and Mollic Gleysol soil, respectively, and generally decreased with pH (R=0.835; α = 0.05) and when bulk density (R=−0.736; α = 0.05) as well as ash content (R=−0.751; α = 0.05) increased. In the case of surface charge, the values ranged from 63.00 to 844.67 μmol g−1 Haplic Fluvisol and Mollic Gleysol, respecively. Organic matter gave significant contributions to the specific surface area and cation exchange capacity due to the large surface area and numerous surface functional groups, containing adsorption sites for water vapour molecules and for ions. The values of cation exchange capacity and specific surface area correlated linearly at the level of R=0.985; α = 0.05.

The effect of aggregation into fractals or microgels on the charge density and the isoionic point of globular proteins

Potentiometric titration curves were obtained for aqueous solutions of native whey protein isolate (WPI) and β-lactoglobulin (β-lg) at different NaCl concentrations. The curves crossed at approximately the same pH, which is considered to be the isoionic point (IIP). Titration with NaCl confirmed that the pH was independent of the salt concentration up to 0.1 M at the IIP, which was 4.9 for WPI and 5.0 for β-lg. Fractal aggregates and microgels of different sizes were formed by heating protein solutions at different pH and different concentrations. The titration curves of the aggregates depended on the type of aggregates, but not on their size. The IIP increased by at most 0.2 pH units after aggregation. For a given pH larger than IIP, the charge density of the proteins (α) was reduced after denaturation and aggregation. The reduction was stronger for microgels than for fractal aggregates. Addition of NaCl or increasing the protein concentration mitigated the effect. Comparison between WPI and β-lg showed that the pH dependence of α was almost the same for pH > 5.0 both for native and aggregated proteins.

Characterization of acid functional groups of carbon dots by nonlinear regression data fitting of potentiometric titration curves

The oxygenated functional groups present on the surface of carbon dots with an average size of 2.7±0.5nm were characterized by a variety of techniques. In particular, we discussed the fit data of potentiometric titration curves using a nonlinear regression method based on the Levenberg–Marquardt algorithm. The results obtained by statistical treatment of the titration curve data showed that the best fit was obtained considering the presence of five Brønsted–Lowry acids on the surface of the carbon dots with constant ionization characteristics of carboxylic acids, cyclic ester, phenolic and pyrone-like groups. The total number of oxygenated acid groups obtained was 5mmolg−1, with approximately 65% (∼2.9mmolg−1) originating from groups with pKa<6. The methodology showed good reproducibility and stability with standard deviations below 5%. The nature of the groups was independent of small variations in experimental conditions, i.e. the mass of carbon dots titrated and initial concentration of HCl solution. Finally, we believe that the methodology used here, together with other characterization techniques, is a simple, fast and powerful tool to characterize the complex acid–base properties of these so interesting and intriguing nanoparticles.

Constant-pH MD Simulations Portray the Protonation and Structural Behavior of Four Decapeptides Designed to Coordinate Cu(2+).

The cyclic decapeptide C-Asp, containing one Asp residue and three His residues, was designed by Fragoso et al. (Chem. Eur. J. 2013, 19, 2076) to bind Cu(2+) exclusively through the side chain groups and mimic copper coordination in metalloproteins. A variant of the cyclodecapeptide where Asp is substituted by Asn (C-Asn) has also been synthesized in addition to the linear ("open") counterparts of both forms (O-Asp and O-Asn), testing the importance of cyclization and the presence of Asp in Cu(2+) coordination (Chem. Eur. J. 2013, 19, 2076; Dalton Trans. 2013, 42, 6182). All peptides formed a major species at neutral pH that was able to coordinate Cu(2+) exclusively through the neutral imidazole groups and the Asp side chain, when present, with C-Asp being the most effective. A detailed description of the protonation behavior of each histidine could help understanding the coordination species being formed in the pH range and eventually further optimizing the peptide's design. However, the standard current methods (NMR titrations) are not very suited for proximal groups titrating in the same pH range. In this work, we used the stochastic titration constant-pH molecular dynamics method to calculate the protonation curves and pKa of each titrable residue in the four decapeptides, in the absence of Cu(2+) ions. The global protonation curves obtained in our simulations are in very good agreement with the existing potentiometric titration curves. The histidines are titrating very closely, and the Asp forms abundant salt bridges with the basic residues, displaying an unusually low pKa value. In addition, we could observe that the four peptides are very unstructured in the absence of copper, and not even the cyclic forms exhibit a significant β-sheet, unlike what could be expected from the presence of β-turn inducer units in this type of scaffold.

Protein adsorption equilibrium and kinetics in multimodal cation exchange resins

Protein adsorption equilibria and kinetics are obtained experimentally for two multimodal cation exchange resins—Nuvia cPrime, which is based on a polymeric matrix, and Capto MMC, which is based on an agarose matrix. In both resins, the ligand contains a phenyl group, a carboxyl group, and a peptide bond but with a different arrangement. Transmission electron microscopy and inverse size exclusion chromatography indicate a bimodal distribution of pores in Nuvia cPrime, including small pores with 10 nm radius and pores larger than 400 nm, and a monodispersed distribution of pores in Capto MMC, averaging 32 nm in radius. Potentiometric titration curves show similar buffering ranges and pKa values for the ligands in both resins and a slightly higher ligand density for Nuvia cPrime. Equilibrium binding capacities for lysozyme and a monoclonal antibody (mAb) are also similar for both resins at comparable pH and salt concentrations, although Capto MMC shows a weaker dependence on salt concentration as a result of its more hydrophobic character. The main difference is the adsorption kinetics of the mAb, which is the larger of the two proteins studied. For both resins, as shown by means of confocal laser scanning miscopy, the adsorption kinetics is controlled by pore diffusion. Capto MMC with its smaller pores has a slower rate of mass transfer than Nuvia cPrime. As a result, for the mAb, much higher column dynamic binding capacities are obtained for Nuvia cPrime than for Capto MMC.

Complex formation equilibria between aluminum(III), gadolinium(III) and yttrium(III) ions and some fluoroquinolone ligands. Potentiometric and spectroscopic study

Complex formation equilibria of aluminum(III), gadolinium(III), and yttrium(III) ions with the fluoroquinolone antibacterials moxifloxacin, ofloxacin, fleroxacin, lomefloxacin, levofloxacin, and ciprofloxacin were studied in aqueous solution by potentiometric and spectroscopic methods. The identity and stability of metal–fluoroquinolone complexes were determined by analyzing potentiometric titration curves (310 K, μ = 0.15 M NaCl, pH range = 2–11, CL/CM = 1 : 1 to 3 : 1, CM = 1.0 mM) with the aid of Hyperquad2006 program. The main species formed in the system may be formulated as MpHqLr (p = 1, q = −2 to 2, r = 1–3, L = fluoroquinolone anion, logarithm of overall stability constant, log βp,q,r = in the range ca. −10 to 45). The stability of complexes is mostly influenced by metal ion properties (ionization potential, ionic radius) indicating partial ionic character of the coordination bond. The complexes were also characterized by spectroscopic measurements: spectrofluorimetry, 1H-NMR, and ESI-MS. Fluorimetric data were evaluated with the aid of HypSpec2014 and indicated the formation of MLr (r = 1–3) complexes with cumulative conditional stability constants significantly lower than the thermodynamic ones. NMR and MS data corroborate potentiometrically determined speciation. Calculated plasma mobilizing capacity of the ligands generally follows the order levofloxacin > moxifloxacin > ciprofloxacin at concentration levels of the ligands higher or equal to ca. 10−4 M.

Quantitative Structure–Activity Relationship Analysis of the Effect of Metoclopramide and Related Compounds on the Surface Ionization of Fumed Silica

Potentiometric titration curves were generated for fumed silica with various concentrations of dissolved metoclopramide. The effects of various benzamide analogs of metoclopramide, which are positively charged in the titration medium and differ solely by their aromatic substituents, as well as lidocaine, which is also structurally analogous but is mainly in the unionized form, were also studied. At sufficiently high pH, pH 7.0 and above, the silica surface charge was independent of the metoclopramide concentration. A reasonable linear relationship with a positive slope was found between the logarithmic octanol–water partition coefficient (log P) values of the compounds and the negative surface charge determined at pH 7.0 and 7.2. These results can be attributed to specific adsorbate–surface interactions rather than concentration effects. The carbonyl oxygens of the benzamide structures most likely form hydrogen bonds with the neutral silanols. The use of positively charged triethylamine and ephedrine resulted in surface charge values that were the least negative in the aforementioned quantitative structure–activity relationship analyses. These results are consistent with ionic interactions between the positively charged aliphatic amine groups and the negatively charged surface silanols occurring simultaneously with the nonionic interactions.

Potentiometric studies on ternary complexes involving some divalent transition metal ions, gallic acid and biologically abundant aliphatic dicarboxylic acids in aqueous solutions

Formation of binary and ternary complexes of the divalent transition metal ions, Cu2+, Ni2+, Co2+ and Zn2+ with gallic acid and the biologically important aliphatic dicarboxylic acids (adipic, succinic, malic, malonic, maleic, tartaric and oxalic acids) were investigated by means of the potentiometric technique at 25 °C and I = 0.10 mol dm−3 NaNO3. The acid-base properties of the ligands were investigated and discussed. The acidity constants of gallic acid and aliphatic dicarboxylic acids were determined and used for determining the stability constants of the binary and ternary complexes formed in the aqueous medium under the above experimental conditions. The formation of the different 1:1 and 1:2 binary complexes and 1:1:1 ternary complexes are inferred from the corresponding potentiometric pH-metric titration curves. The ternary complex formation was found to occur in a stepwise manner. The stability constants of these binary and ternary systems were calculated. The values of Δ log K, percentage of relative stabilization (%R.S.) and log X were evaluated and discussed. The concentration distribution of the various complex species formed in solution was evaluated and discussed. The mode of chelation of ternary complexes formed was ascertained by conductivity measurements.

STUDY COMPLEXING AND TECHNOLOGICAL PROPERTIES OF REAGENTS FOR OIL PRODUCTION, OBTAINED BY MODIFYING SULPHITE LIQUOR PHOSPHONIC

The possibility of formation of complex compounds of phosphonic acid groups nitriltrimetilenfosfonovoy (NTF) and sodium tripolyphosphate (TPP) with aromatic structural units sulfite liquor (lignosulphonate technical). A comparative analysis of potentiometric titration curves of solutions of sulfite liquors brine lead acetate and potentiometric curves after modification phenylpropanoic groups sulfite liquor polyvalent metal salts as an example of ferrous sulfate, sodium dichromate, as well as compounds containing phosphonic the example of NTF and TPF. The effect of different modifiers on properties of the resulting complex compounds used in the drilling technology as chemicals, reagents, and viscosity reducers stabilizers technological properties of drilling fluids. Test results obtained complex compounds with respect to the mud showed that modification of lignosulfonate phosphonic groups can increase the thermal stability of parameters of the solution. It is shown that the modification of phenylpropane units lignosulfonate contributes to the formation of complex compounds of at least two kinds: by creating coordination bonds cation - electrophile with phenylpropanoic groups and by replacing the less electronegative anion nucleophile-phenylpropane units on the phosphonate ion. Found that the phosphonic groups of NTF and TPF may form complex compounds with polymeric structures having not only aliphatic but also aromatic structure for example sulphite liquors phenylpropane units.