BUFFER SYSTEMS BASED ON AMINOMETANESULPHONATE AND MONOETHANOLAMMONIUM N-ALKYLAMINOMETHANESULPHONATES

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.

Cationic dyes and their use for the quantitative extraction-photometric determination of higher carboxylic acids

Cationic dyes of various natures have been investigated in order to select a dye that is stable under strongly alkaline conditions and applicable for the quantitative extraction-photometric determination of higher carboxylic acids. The nature of the dye, solvent, the length of the hydrocarbon radical of carboxylic acids and the pH of the aqueous phase for the extraction of ionic associates of higher carboxylic acids with cationic dye with pyronin G were experimentally studied. The study substantiates the practical application of the cationic dye pyronin G as an effective reagent for the quantitative extraction-photometric determination of higher carboxylic acids.

Azo-substituted ethoxyacridine – reagents for the extraction-photometric determination of indium(III)

The associates of bromo-indate with azo-substituted ethoxyacridine have been studied by spectrophoto-metric method. It has been found that the associates are well extracted with a mixture of chloroform acetone (4:1). The optimum volume of aqueous and organic phase is equal to 5 ml. The molar ratio of the components in the extractable compounds was studied by the methods of isomolar series, equilibrium shift and a straight line. It was found that bromo-indate associated with azo-ethoxyacridines (AE) in a ratio of 1:1. Study of the effect of foreign ions on the accuracy of the determination of indium with azo-substituted ethoxyacridine showed that the number of ions does not interfere (in parentheses are multiple relationships to indium ions); CdII (1200), NH4+ (4000), Zn2+ (1500), CoII (1100), NiII (1050), CuII (500), FeII (4000), PbII (250), Nb (250), TaV (270), Al3+ (2000), ReVII (140), B3+ (410), C2O42- (1900), CH3COO- (1300), ascorbic acid (270), citrate ion (3500), tartrates (4000), EDTA (3700). Number of ions interfered the determination: TlIII (1), FeIII (1), Ga3+ (1), HgII (1), SbV (1), AuIII (1), thiourea (4). It was studied formation and extraction of associates of bromo-indate with AEADPA (2-ethoxy-6-(4-N,N-dipropylphenylazo)-9-aminoacridine) and AEADEA (2-ethoxy-6-(N,N-ethylphenylazo)-9-aminoacridine). The maxima of light absorption of bromo-indate with AEADPA is observed at 530 nm, and the AEADEA at 515 nm. The physico-chemical and analytical characteristics of the azo-substituted ethoxyacridines and their ionic associates with indium bromide acid complexes (λmax ε, βkD, D, R%) were determined. It was shown that bromo-indate compounds with azo-substituted ethoxyacridines are ionic associates, the molar ratios of the components in which are: [İn III] : [Br -] : R + = 1:4:1. Highly efficient extraction-photometric methods have been developed for the determination of trace amounts of indium in various objects.

Anti-microbial activity of heterocyclic cationic surface-active substances

Annotation. The development and rapid pace of the spread of resistance to antimicrobial agents predetermines the search for new methods of counteracting pathogenic and conditionally pathogenic microorganisms. In this context, studies of the antimicrobial activity of newly synthesized chemicals, which in the future can be considered as candidates for antiseptic and disinfectants, are relevant. The aim of the work was to determine the antimicrobial activity of new ionic associates based on the surface-active cetylpyridinium cation with respect to certain opportunistic microorganisms. The antimicrobial activity of four ionic associates based on the cetylpyridinium cation with respect to clinical isolates of E. coli, P. vulgaris, K. pneumonia, P. aeruginosa, S. aureus, as well as the collection test strains of S. aureus ATCC 25923, E. coli ATCC 29522 and P. aeruginosa ATCC 27853 was studied. Screening studies were performed by the disk diffusion method. With substances that showed an antimicrobial effect, quantitative studies were carried out by the method of serial macro-dilutions in a liquid nutrient media. Screening studies revealed the antibacterial activity of the substances against E. coli ATCC 25923, E. coli (clinical isolate), P. vulgaris and K. pneumonia. With these microorganisms quantitative studies were carried out with the determination of the minimum inhibitory and minimum bactericidal concentrations. The most pronounced antimicrobial activity for the investigated microflora was shown by tetraphenylborate and cetylpyridinium perchlorate. The MIC and MBC values of these substances ranged between 1.625–3.125 mmol / L and 3.125–12.5 mmol / L, respectively. The studied associates showed high antimicrobial activity against representatives of the Enterobacteriaceae family in in vitro studies. Promising is the further study of the effect of the counter-anion associates of cationic surfactants on the biofilm formation of conditionally pathogenic microorganisms.

Visual test determination of trace amounts of germanium in the form of an ionic associate of 12-molybdogermanate with astrafloxin

Sorption-colorimetric and naked eye determination of germanium as ion associates of GeMo O 4– with triphenylmethane dyes is described. The sorption of the ionic associates (IA) of 12molybdogermanat with astrafloxin (AF) on filter paper was studied. The colored scales for naked eye detection and dependence of chromaticity coordinates from the germanium (IV) concentration were obtained. The methods were applied to the determination of germanium (IV) in coked coal, iron ore, and in waters in the concentration range from 4•10–8 to 1•10–6 mol•L–1. The developed test-systems for the determination of Germanium in natural and technological objects were tested in the course of training students of chemistry of Kryvyi Rih State Pedagogical University.

Cloud Point Extraction Of Cationic Surfactants And Their Ionic Associates With Sodium Dodecyl Sulfate

The distribution of individual cationic surfactants and their ionic associates with the anionic surfactant in the cloud point extraction systems, based on non-ionic surfactant OP-7 was investigated. Determined that the dependence of the extraction degree of halides alkylpyridiniums on carboxylic change length in optimal conditions for extraction is characterized by the existence of maximum for cationic surfactant where n = 12. Decrease as well as increase in carboxylic change length of cation of alkylpyridiniums diminishes the effectiveness of their extraction into the surfactant-rich phase. The peculiarities of inter phase distribution of ionic associates cationic surfactant – anionic surfactant in the micellar extraction systems are investigated. It was shown, that with the increase in carboxylic change length of cationic surfactant the dependence of extraction degree of associates with anionic surfactant is characterized by the existence of the maximum. Most effective into the surfactant-rich phase extracted of ionic associates of three- and tetradecylpyridinium. Decreasing and increasing of hydrophobicity of alkylpyridiniums diminishes the effectiveness of extraction of associates. The established effects are explained by the hydrophobic correspondence between the substrate and the surfactant-rich phase of non-ionic surfactant.

Azo-substituted ethoxyacridine – reagents for the extraction-photometric determination of gallium

The associates of halide (chloride) complexes of gallim azo-substituted ethoxyacridine have been studied by spectrophotometric method. It has been found that the associates are well extracted with a mixture of dichloroethane-acetone (3:2). The optimum volume of aqueous and organic phase is equal to 5 ml. The molar ratio of the components in the extractable compounds was studied by the methods of isomolar series, equilibrium shift and a straight line. It was found that gallium chloride associated with azo-ethoxyacridines (AE) in a ratio of 1:1. It was studied formation and extraction of associates of gallium chloride with AEADPA (2-ethoxy-6-(4-N,N-dipropylphenylazo)-9-aminoacridine) and AEAN (2-ethoxy-6-(2-hydroxynaphthylazo)-9aminoacridine). The maxima of light absorption of gallium chloride with AEADPA is observed at 520 nm, and the AEAN at 510 nm. The light absorption of the extracts of associates coincides with the absorption maxima of azoethoxyacridines, which indicates the electrostatic character of the interaction and the formation of complexes. Study of the effect of foreign ions on the accuracy of the determination of gallium with azo-substituted ethoxyacridine showed that the number of ions does not interfere (in parentheses are multiple relationships to gallium ions); Zn2+ (2000), NiII (1500), CuII (2500), CoII (1400), Cr III(1100), PbI (2250), Al3+(1600), Cd2+(700), FeII (1050), ReVII (500), PdIII (1200), Tl (2500). Number of ions interfered the determination: TeIV(1), FeIII (1), AuIII (1), SbV(1), TlIII(1), SeIV(3). The physico-chemical and analytical characteristics of the azo-substituted ethoxyacridines and their ionic associates with chloride gallium acidic complexes (λmax ε, βkD, D, R%) were determined. It was shown that chloro-gallium compounds with azo-substituted ethoxyacridines are ionic associates, the molar ratios of the components in which are: [Ga3+] : [Cl-] : R+ = 1:4:1.

The New Sorbent and the Method of Sulphide and Mercaptans Removal from the Enterprises of Oil and Gas Complex Atmospheric Air

The materials and methods for removing hydrogen sulphide and mercaptans from the air, aimed to improve the areas of oil and gas complex enterprises in health respect, related to the primary processing of oil, natural gas and gas condensate, are often associated with the processing of raw materials containing a significant amount of sulphur compounds such as hydrogen sulphide, mercaptans and others. The enterprises, considering premises for various purposes, in spite of all the measures taken, produce small, below the exposure limits of the amount of hydrogen sulphide and low molecular weight mercaptans while their operation. Despite the fact, that the amount of hydrogen sulphide and mercaptans, contained in ambient, especially in indoor air, is lower than TVL, the operating personnel is constantly exposed to those components. The basis of the sorbent is flask, highly siliceous material. On the surface of the beads adsorbed diethanolamine the acidic gases form fairly strong ionic associates. In the article the mechanism of associates formation, the sorption mechanism for trapping hydrogen sulphide as well as the characteristics of the absorber circuit diagram for cleaning the air of hydrogen sulphide and mercaptans are shown.

Spectrophotometric determination of trace amounts of iodide-ions in form of ionic associate with brilliant green using electrochemical oxidation

A combined method involving electrochemical oxidation of iodide to iodate at a platinum electrode followed by extraction in CCl4 of ionic associates of iodine-iodide complexes with brilliant green, formed in excess of iodide, was developed for the spectrophotometric quantification of iodide. The slope of the calibration curve yields a molar extinction coefficient of ɛ = 3·105 L mol−1cm−1. This method can be used for the quantification of iodide in the concentration range of 3·10−7 − 3·10−6 mol L−1 with a detection limit of 5·10−8 mol L−1. The interfering effect of other ions on the determination of the iodide concentration was also investigated. The method was successfully applied for the determination of iodide in real samples of NaCl and spring water. Relative standard deviation is 1–2%.