Complexometric Titration Research Articles

Application of Herbal Medicine in Cu2+ Removal from Water and Comparison of its Detection Methods

In order to utilize discarded herbal medicine to treat heavy metal pollution in water, various herbal medicines were selected to explore their abilities of metal ions removal. In this experiment, copper ion was used as targeted heavy metal ion and two different treatments of several herbal medicines were compared on the effect of the copper ion removal ability. At the evaluating stage, four metal ion detection methods were employed and analyzed in this herbal medicine Cu2+ removal application. The results showed that directly soaking herbal medicine in the copper aqueous solution was more effective and easier to operate. Iodometry method and EDTA complexometric titration with xylenol orange as indicator were accurate and time-saving in the measurement of copper removal rate. In addition, the EDTA complexometric titration is also applicable in the detection of other metal ions. This experiment provided a basis for the implementation and application of herbal medicine in the deposition of metal ions in polluted water.

Investigation of the Effect of Volumetric Hydrophobization on the Kinetics of Mass Transfer Processes Occurring in Cement Concretes during Corrosion.

The entry of aggressive substances into the pore structure of concrete causes the development of corrosion processes and leads to the destruction of the cement stone structure. Hydrophobic additives provide high density and low permeability and are an effective barrier to the penetration of aggressive substances into the structure of cement stone. To assess the contribution of hydrophobization to the durability of the structure, it is necessary to know how much the processes of corrosive mass transfer slow down. To study the properties, structure and composition of the materials studied in the work (solid and liquid phases) before and after exposure to liquid-aggressive media, experimental studies were carried out using chemical and physicochemical analysis methods: determination of density, water absorption, porosity, water absorption and strength of cement stone; differential thermal analysis; quantitative analysis of calcium cations in liquid medium by complexometric titration. The article presents the results of studies of the effect on the operational characteristics of the introduction of a hydrophobic additive of calcium stearate into the cement mixture at the stage of concrete production. The effectiveness of volumetric hydrophobization was evaluated to prevent the penetration of an aggressive chloride-containing medium into the pore structure of concrete destruction and the leaching of calcium-containing components of cement stone. It was found that the introduction of calcium stearate in an amount of 0.8-1.3% by weight of cement increases the service life of a concrete product during corrosion in liquid chloride-containing media with a high degree of aggressiveness by four times.

Novel titrimetric method for the determination of rosuvastatin in pure form

In this experiment assay of Rosuvastatin was performed by titrimetric method. The titration performed is a complexometric titration. The complexometric titration used is an easy, inexpensive volumetric titration method. This method is based on rection of calcium with a solution of disodium ethylenediaminotetraacetate (EDTA). Complex of calcium and EDTA is formed. Erichrome black Tis used as an indicator in this complexometric titration. At pH 12-13, Erichrome black T changes the color from pink to blue. The appearance blue color is determined to be the endpoint of this experiment. The titrations were carried out in triplicates and the average reading was taken to calculate the percentage assay. The percentage purity was found to be 103.05%

Resampling for estimation of parameters uncertainty in genetic algorithm based model fitting

Resampling methods draw samples from the observed data to draw certain conclusions about the population of interest.The study is the employment of resampling to the calculation of parameters uncertainty in hard model fitting of chemical and spectrochemical data, assisted by genetic algorithm. Four data sets are investigated including: a simulated two steps of complexometric spectrophotometric titration data, a real data from IgG purification by ion exchange chromatography, one 1H NMR spectrum from a real metabolomics data set, and a simulated metabolomics 1H NMR spectrum. In the first data, the logarithm of formation constants in the first and second steps were 4.500 and 7.200, respectively. The mean of estimated parameters and standard deviations using the proposed method were obtained as 4.504 ± 0.005 and 7.205 ± 0.017 by removing around half of the samples while for NGLM algorithm and Hessian matrix were 4.503 ± 0.005 and 7.203 ± 0.018. In the second data, desorption coefficient (kdes,0), equilibrium coefficient (Keq,0), and a constant parameter that describes ion exchange characteristics (β) were well estimated with root mean square error (RMSE) of 0.031 mg mL−1. In the third and last data sets, parameters including chemical shifts and intensity of each metabolite were well calculated with low relative error of 4.23 × 10−4. The estimated uncertainty of parameters were different. In some cases, the means of estimated parameters were dependent of the number of eliminated samples in resampling. Effect of number of variables in data and model deficiency on the results from resampling was investigated. Due to the complexity of the mentioned datasets, use of resampling and GA is useful and important strategy for acquiring parameter mean and uncertainty, when we are not able to determine the Hessian matrix.

Возможности применения промышленной воды предприятий нефтегазового комплекса для получения противопожарных пен

Introduction. One of the distinctive features of fires at oil and gas facilities is the need for constant replenishment of the water supply used by fire departments in the shortest possible time. There is a need for the use of industrial waters in the organization of extinguishing fires of oil and petroleum products. In this paper discusses the features of the usage of industrial waters to obtain premixes of foaming agents used for foam fire extinguishing. For this purpose, an assessment of the technical indicators of the quality of working solutions of foaming agents was carried out using models of drinking, circulating and seawater. Goals and objectives. Conducting research on the foaming ability of standard foaming agents with water, in its composition as close as possible to the requirements of regulatory documents to recycled industrial water. Methods. The following laboratory methods were used in the work: volumetric analysis, complexometric titration, tensiometry, standard methods of testing foaming agents to assess their quality. Results and discussion. The total salinity in waters of various types increases in the range from drinking to sea water. Recycled water at the maximum values of salt additives occupies an average intermediate value, including in terms of water hardness, which gave a difference in foaming characteristics. The difference between the hardness of drinking and model circulating water is significant, which affects the foaming due to the flow of ionic processes in such systems and probably leads to a decrease in expansion factor of the resulting air-mechanical foam. The possibility of using industrial waters to produce firefighting foams has been experimentally confirmed. A model of recycled industrial water has been developed, which made it possible to evaluate the extinguishing efficiency of foam obtained on its basis in laboratory conditions. Conclusion. A comprehensive analysis of the obtained data shows that foaming agents, application field of which does not imply the use of sea water, can be used to prepare premixes in ordinary drinking water, as well as in recycled water used in the technological cycles of industrial enterprises, which in some cases simplifies the practical issues of obtaining fire-fighting foams for extinguishing fires. Keywords: foaming agents; recycled industrial water; water hardness; air-mechanical foam.

Integrating Instruction Strategy of Theory and Practice in Analytical Chemistry: Taking Complexometric Titration as an Example

Integrating Instruction Strategy of Theory and Practice in Analytical Chemistry: Taking Complexometric Titration as an Example

Composite Cement Materials Based on β-Tricalcium Phosphate, Calcium Sulfate, and a Mixture of Polyvinyl Alcohol and Polyvinylpyrrolidone Intended for Osteanagenesis

The primary purpose of the study, presented in this article, was to obtain a composite cement material intended for osteanagenesis. The β-tricalcium phosphate powder (β-TCP, β-Ca3(PO4)2) was obtained by the liquid-phase method. Setting and hardening of the cement system were achieved by adding calcium sulfate hemihydrate (CSH, CaSO4·1/2H2O). An aqueous solution of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), and a PVA/PVP mixture were used as a polymer component. The methods of capillary viscometry and Fourier-transform infrared spectroscopy (FTIR) revealed the formation of intermolecular hydrogen bonds between polymer components, which determines the good miscibility of polymers. The physicochemical properties of the synthesized materials were characterized by X-ray diffraction (XRD) and FTIR methods, and the added amount of polymers does not significantly influence the processes of phase formation and crystallization of the system. The size of crystallites CSD remained in the range of 32-36 nm, regardless of the ratio of polymer components. The influence of the composition of composites on their solubility was investigated. In view of the lower solubility of pure β-TCP, as compared to calcium sulfate dihydrate (CSD, CaSO4·2H2O), the solubility of composite materials is determined to a greater degree by the CSD solubility. Complexometric titration showed that the interaction between PVA and PVP impeded the diffusion of calcium ions, and at a ratio of PVA to PVP of 1/1, the smallest exit of calcium ions from the system is observed. The cytotoxicity analysis results allowed us to establish the fact that the viability of human macrophages in the presence of the samples varied from 80% to 125% as compared to the control.

Development and Validation of Analytical Method for Estimation of Calcium in Herbomineral Formulation by Atomic Absorption Spectrophotometry

Calcium determination is normally done by conventional titrimetric methods (complexometric titration). In this study, a simple, precise, accurate, rapid and sensitive method has been developed for calcium (Ca) determination in Maxcal-C Tablet (herbo-mineral formulation) and its raw materials by Atomic Absorption Spectrophotometer (AAS). For complete digestion of the sample, closed vessel wet digestion technique was used with 69% HNO3 and 30% H2O2 (7:1) as digestive solvents. Analysis was performed on AAS (AA-6300) at λmax 422.7 nm. Calcium nitrate Ca(NO3)2 was used as a standard for Calcium and the linearity of the standard was excellent over a concentration range of 0.5 to 20 μgmL-1. The regression coefficient (r2) was 0.999. For intraday and interday precision % RSD was obtained between 0.48%-1.95% and 3.48%-5.01%, respectively which complied with the standard range for AAS. Recovery was achieved at 93.24%, 99.73%, 101.75% for 3 levels of spikes (80%, 100%, 120%) respectively, which complied with the standard range 75- 125% for AAS. However, the AAS method produced accurate and reproducible results and also overcame the colour and other ions interference, which are common problems with the titrimetric method. The results of both techniques (the AAS method and the titrimetric method) were compared, which showed good estimation by AAS.

Mapping of well water and soil parameters in a selected grama niladhari division of Gampaha district

This study intends to fill an essential knowledge gap in the field of environmental information in Sri Lanka, by providing a reliable data bank supporting the information of existing chemical species of two important components, well water and soil. Further, this study would provide reference information for future work and aid in explaining the changes that would occur due to changes in the chemical composition of the environment. Thalawathuhenpita North Grama Niladhari division was selected as the initial site of study and sampling was done from 23 sites, where two representative samples of each soil and well water were collected from each site. This study investigates the well water quality parameters such as pH determined by a pH meter, hardness and Calcium content using complexometric titrations, nitrate content using a spectrometric analysis, Iron content using a colorimetric analysis, and soil quality parameters such as active pH using a pH meter, water-soluble and exchangeable cations(Na+,Ca2+,K+)using a flame photometer and complexometric titration, organic matter content using a redox titration, iron content and nitrate content as mentioned above. The readings were duplicated and reported as means ± standard deviation, and contour maps were produced using Surfer ® (Golden Software, LLC). Maps depict the scope of variation of the determined parameters within the selected area and highlight the point that it is crucial to monitor the environmental resources chemically in a regular manner to address the environmental problems that may occur in the future.

Condensed Combustion Products Characteristics of HTPB/AP/Al Propellants under Solid Rocket Motor Conditions

Condensed combustion products (CCPs) generated during the combustion of aluminized propellants can reflect invaluable information about the combustion mechanisms of propellants. CCPs of hydroxyl-terminated polybutadiene/ammonium perchlorate/aluminum (HTPB/AP/Al) propellants were collected using an experimental apparatus capable of controlling pressure fluctuations within 0.3 MPa, and their microscopic morphologies, particle size distributions, and chemical compositions were characterized using a scanning electron microscope (SEM), laser particle size analyzer, energy disperse spectroscopy (EDS), X-ray diffraction (XRD) and complexometric titration. The results showed that the size of CCPs presented a bimodal distribution, with modes at ~5 µm and ~100 µm; particles less than 2 µm were spherical, with smooth surfaces. The main components of CCPs were C, AlN, AlCl3, Al2O3, Fe2O3 and Al, with Al2O3 being the most abundant. The combustion efficiency of aluminum increased by 3.27% when the size of virgin aluminum particles decreased from 23 µm to 13 µm, but the content of catocene (a burning-rate catalyst) and fine AP (1 µm) had little effect on combustion efficiency. Higher combustion efficiencies and smaller agglomeration sizes can be achieved at higher pressures, due to the positive correlation between pressure and the driving forces for aluminum particles exciting the burning surface.

Experience of using the evaluations of the repeatability and reproducibility in compa­ ring test methods according to ISO 5725-6 "Accuracy (trueness and preci­ sion) of methods and measurement results. Part 6. Using precision values in practice"

The trueness and precision indicators of two methods — complexometric titration and atomic absorption spectrometry (AAS) — were evaluated to select a method that would provide a higher accuracy of copper determination in a brass coating. In the titrimetric method of copper determination, the brass coating was dissolved in a mixture of ammonia and hydrogen peroxide and titrated with a solution of Trilon В in the presence of xylenol orange indicator, whereas for the atomic absorption method the coating was dissolved in nitric acid and the test solution was measured on an atomic absorption spectrometer. Two laboratories took part in the experiment. The results of measurements and the calculated precision indicators (repeat­ability and reproducibility) for both methods are presented. The intra-laboratory (intermediate precision) and general precision of the methods was compared using the Fisher test, whereas the overall average cop­ per content was compared with the certified value of a standard brass sample in accordance with ISO 5725-6 "Accuracy (trueness and precision) of methods and measurement results. Part 6. Using precision values in practice. " It is shown that the atomic absorption method is the most accurate among two consid­ered methods for determining the mass content of copper in a brass coating, as it has acceptable indicators of precision and trueness.

Gravimetric Complexometric Titration Method to Determine Mass Fraction of Ethylenediaminetetraacetic Acid Disodium Salt Dihydrate in Candidate-Certified Reference Materials

Titrations are a group of techniques that have contributed considerably to developing the chemical industry and chemistry itself. Currently, the Consultative Committee for Amount of Substance has recognized titration as one of the primary methods for determining the amount of substance. In this context, an accurate gravimetric complexometric titration method was implemented to determine the purity of ethylenediaminetetraacetic acid (EDTA) disodium salt dihydrate using a lead nitrate-certified reference material (CRM). The titration reaction was followed potentiometrically using a lead ion-selective electrode. The equivalence point was found by the inflection of a non-parametric regression line that fits the experimental data. The titrations were made in diluted ammonium hydroxide media and sodium tartrate was added to avoid the lead hydroxide precipitation that occurs at high pH. The effect of both concentrations, ammonium hydroxide and sodium tartrate, were evaluated by a Box-Behnken experimental design. A complete uncertainty statement for the measurement method is presented in terms of the International System of Units (SI). The combined relative standard uncertainty of the measurement results is 0.034 % for the purity of the EDTA disodium salt. The atomic weight of the lead that applies to the lead nitrate CRM was determined with mass spectrometry to decrease the uncertainty budget contribution of this parameter which, otherwise, would have been the most important. The main sources of uncertainty were the mass of the EDTA solution for titration blanks, the purity of the lead nitrate CRM, and the precision of the equivalence point determination. The method was evaluated using an EDTA disodium salt dihydrate CRM and no significant bias was found. Finally, the results indicated that the developed method could be used for the value assignment of the mass fraction of EDTA disodium salt dihydrate to produce CRMs.

Penetapan Kadar Kalsium Pada Daun Krokot (Portulaca Oleracea L.) Secara Kompleksometri

Research on the determination of calcium levels in purslane (Portulaca oleracea L.) leaves has been carried out using the indirect complexometric titration method. Fresh purslane leaves were extracted using 3N HC1, dissolved calcium was added to an excess of 0.05 M NazEDTA solution and the excess Na EDTA was titrated with 0.05 M MgSO4 solution using an EBT indicator. Obtained calcium levels in fresh purslane leaves of 0.1503% w/w.

Electrochemical sensor based on ion-selective membrane of silica/polyaniline nano-composites for selective determination of uranyl ions

Life threatening impacts of uranium have necessitated its detection and determination in economically feasible way before it arrives in living bodies. Therefore, a new form of UO22+ ion-selective electrode has been fabricated based on membrane of silica/polyaniline core-shell nano-composites, in-spite of traditionally used ionophores, because of intrinsically conducting nature of polyaniline. For the synthesis of these nano-composites, silica has been extracted from rice straw in its cristobalite form, whereas the layer of polyaniline shell has been grafted on silica nanoparticles through in-situ chemical oxidative polymerization technique by cautiously maintaining the electro-active nature of these core-shell nano-composites. The chemical composition, purity, topography, morphology and surface polarity of this nano-composite assembly have been studied through various spectroscopic techniques such as, FT-IR, EDS, FESEM, UV–Vis, DLS and Raman spectroscopy. The results confirm that silica/polyaniline nano-composites have been synthesized with desired semi-cavities and electrostatic surface charge, which is responsible for binding with target cation, i.e., UO22+for its potentiometric determination in aqueous medium even in the presence of interfering metal ions. The designed potentiometric sensor has shown fast and stable linear response in concentration range of 1 × 10−6 to 1 × 10−2 M with the limit of detection of 1.4 × 10−7 M which is 100-folds lower than the detection limit calculated using spectrofluorometry. In addition to this, the proposed UO22+ion-selective electrode has been successfully employed as an indicator electrode for the determination of uranyl ions in complexometric titration and for the estimation of UO22+ions in real life based environmental sample, i.e., soil.

Studies on the application of Zirconia nanoparticles for the removal of heavy metal (Pb (II)) from the aqueous solution

In this present study, Zirconia nanoparticles (nanosorbent) have been prepared by both chemical and green methods. The nano sorbent was characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) - EDAX and FT-IR techniques. The XRD data revealed the mean crystalline sizes of adsorbent. The surface morphology of adsorbent was studied by SEM. Removal of lead (II) was studied by adsorption of nano sorbent. An unadsorbed lead concentration was found using complexometric titration against standard EDTA with EBT as an indicator. The factors such as dosage, pH and concentration of Pb (II) were examined to find the efficiency of the process. Adsorption isotherms such as Freundlich and Langmuir isotherm models confirm that the reaction is spontaneous one. Kinetic studies proves that it follows Pseudo-second order kinetic model and was found to be the best fitted model.

Synthesis, Characterization and Photophysical Study of 4,4’-Diamino-2,2’-stilbenedisulfonate with Lanthanide Ions Complexes

Complex of 4,4’-diamino-2,2’-stilbenedisulfonic acid (DSD) with trivalent lanthanide ions Eu3+ and Tb3+ were prepared at the ratio of 3:1 (DSD:Ln). The complexes with ions present in the form of powder show black (Eu3+) and brown (Tb3+) colors. The complexometric titration and CHN elemental analysis suggest that these complexes have the general formula Eu(C14H12N2SO3SO3H)3∙3H2O and Tb(C14H12N2SO3SO3H)2(CF3SO3)∙3H2O. The shift of the 330 nm band for DSD to a longer wavelength in the infrared spectra of the complexes and the disappearance of the bands at 2921 and 2623 cm-1 are indicative of the formation of complexes with ions Eu3+ and Tb3+. Thermal analysis shows that DSD is thermally stable up to 573 K and the decomposition process of the complexes shows two and three mass losses for ions Eu3+ and Tb3+, respectively. The analysis of luminescence indicates that the complexes do not present the emission from the lanthanide moiety in the visible region. This may be related to the ligand triplet states, which are probably at lower energy than the emission state of the Eu3+ (5D0) and Tb3+ (5D4) ions.

Study of dynamics of accumulation of tanning substances in raw materials of plants of the genus Geum L. flora of Ukraine

Recently, in the pharmaceutical market, much attention is paid to medicinal products obtained from medicinal plant raw materials. Of great current interest is a search for new plants with sufficient domestic raw material base in order to introduce them into medical practice as well as to develop herbal preparations.
 Promising sources of medicinal plant raw materials for the development of herbal preparations with antimicrobial, astringent, anti-inflammatory and hemostatic properties are species of Gravilate genus (Geum L.), which accumulate a wide range of biologically active substances, including polyphenols.
 Plants of Geum L. genus (Gravilate) belong to Rosoideae (Rosaceae family). Two species, Geum urbanum L. (Wood Avens) and G. montanum L. (Mountain Gravilate), grow in Ukraine, and are used in folk medicine as anti-inflammatory, astringent, hemostatic and wound healing agents.
 A significant amount of research articles devoted to the chemical composition and use of Geum L. species indicate the prospects for the study of domestic raw materials of Ukrainian flora.
 An aimof the present study was to quantify tannins and oxidizable phenolic compounds in the vegetative organs of G. urbanum L. and G. montanum L.
 The objects of the study were herb and rhizomes with roots of G. urbanum L. and G. montanum L. harvested in Sumskaya and Ivano-Frankivsk regions in April–September 2020–2021. The content of oxidizable phenolic compounds and tannins was determined by permanganometric titration and complexometric titration. The results obtained were in the range from 8.30% to 28.10%, and 2.66% to 14.35%, respectively.
 As a result, in herb and rhizomes with roots of G. urbanum L. and G. montanum L., oxidizable phenolic compounds and tannins were quantified using permanganometric titration and complexometric titration. Taking into account the high content of tannins in vegetative organs of the studied Geum species, these species can be classified as tannin-bearing plant materials. In G. urbanum L. herb, the maximum content of tannins was determined at flowering stage, while in rhizomes with roots – at the end of the vegetative stage (in autumn). Given the data obtained, the abovementioned vegetative stages are set as optimal for the procurement of G. urbanum L. plant materials.

Selective flocculation and floc-flotation of iron bearing mineral slimes

The mineral processing of friable iron ores usually generates ultrafine (smaller than 15 µm) particles, normally called slimes, which usually have a high iron grade and are usually disposed into tailings dam. The traditional mineral process techniques for iron ore do not work efficiently with ultrafines; however, selective flocculation is an alternative to concentrate that fraction. The physical-chemical treatment of iron ore slime was studied here, on a bench scale, based on the scientific foundations of selective flocculation and flotation. Samples of slimes from two Brazilian iron ore processing plants (CEII and VGII) and industrial process waters were used in the tests. Complexometric titration of calcium and magnesium indicated that the process waters were adequate for selective flocculation. Only selective flocculation, even under optimum conditions, did not achieve good results. However, its use prior to flotation led to promising results. The VGII sample has stood out, for which the final concentrate achieved 60.1 % of Fe, the mass recovery was 64.5 % and 13.5 % of Fe in the tailing, resulting selectivity index of 6.58, only with one stage of selective flocculation and one stage of flotation.

СВОЙСТВА ЭЛЕКТРОЛИТИЧЕСКИХ ЦИНК-НИКЕЛЕВЫХ СПЛАВОВ, ОСАЖДЕННЫХ ИЗ СЛАБОКИСЛЫХ ХЛОРИДНЫХ ЭЛЕКТРОЛИТОВ

The effect of electrolysis parameters on the composition and structure of zinc–nickel coatings during their electrodeposition on a copper substrate from a weakly acidic chloride electrolyte with a Zn(II)/Ni(II) ratio of 1 was studied in this work. The chemical composition of the electrolytes was controlled by complexometric titration. The phase composition was studied using a Rigaku Ultima IV X-ray diffractometer. The gross composition was determined using a JEOL JSM-6460LV scanning electron microscope with computer control. It has been established that an increase in the current density increases the deposition rate of the alloy. It is shown that an increase in temperature leads to an increase in the proportion of nickel in the alloy and an increase in the rate of nickel deposition. An increase in temperature does not affect the rate of zinc deposition. At the same time, at temperatures below 60 °C, the deposition of the alloy is anomalous; at higher temperatures, the deposition becomes normal. The open and total porosity of the coating was determined, it was found that there is no open porosity, the total porosity is about 50%.

Исследование адсорбционной активности энтеросорбента на основе гидролизного лигнина

Enterosorbents based on lignin hydrolised are able to adsorb in the intestine different kinds of toxins, drugs, salts of heavy metals etc. Nowadays, such drugs are widely applied during the treatment of the adults and children from the first year of life due to its safety and proven efficacy. Objective. To study the morphology and the adsorption centers on the surface of the enterosorbent "Filtrum-STI" based on lignin hydrolised. To develop a methodology for determination the adsorption activity of the drug "Filtrum-STI" and to measure qualitatively and quantitatively its adsorption activity to low molecular weight toxins and heavy metals. Materials and methods. The morphology of the sample’s surface was investigated on an Olympus BX-51 optical microscope. IR spectra were obtained using a Thermo Nicolet Nexus 470 FT-IR infrared Fourier spectrometer. Visual identification of the adsorption activity of the enterosorbent was carried out using methylene blue and methyl orange, recommended by the RF SPh as models of low molecular weight toxins. The methodology of determination the adsorption activity to heavy metal cations was developed and the measurements of this activity were carried out using reverse complexometric titration towards Pb2+ cation. Results. Micrographs of the sample "Filtrum-STI" demonstrate the heterogeneity of its surface morphology, the tablet consists of small particles. IR spectroscopy confirmed the presence of active adsorption centers on the surface of lignin hydrolysed. Adsorption of low molecular weight toxins from aqueous solutions was obviously revealed after 15 minutes for all toxins. It is estimated that the adsorption activity of the drug is preserved at physiological pH. The mass content of adsorbed Pb2+ cations was determined by the method of reverse complexometric titration, was demonstrated that w = 19.44 ± 0.92% of cations were adsorbed. Conclusion. A methodology of the determination the adsorption activity of the enterosorbent "Filtrum-STI" was developed and successfully tested, it allowed to confirm the high adsorption properties of the studied drug to a wide range of markers in various media. Key words: enterosorbent, lignin hydrolysed, "Filtrum-STI", adsorption activity, toxins, adsorption centers