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The main methods for the determination of local anesthetics are considered, and their advantages and disadvantages are discussed. After the systematization of published data, it was established that the greatest number of works were devoted to the determination of novocaine, lidocaine, and ultracaine; therefore, methods for their determination are considered separately. It was demonstrated that the extraction and sorption preconcentration of local anesthetics as ion associates with chromogenic organic reagents is promising. It was substantiated that the development of combined rapid and sensitive extraction-photometric, sorptionspectroscopic, and colorimetric methods for the determination of novocaine, lidocaine, and ultracaine with chromogenic organic reagents in different test materials is a problem of considerable current interest. Keywords: local anesthetic agents, novocaine, lidocaine, ultracaine, combined determination methods, GENERAL CHARACTERISTIC OF LOCAL ANESTHETIC AGENTS Local anesthetics (from the Greek anesthesis, insensibility: an-, without + aisthesis, feeling) are selective agents to be applied to peripheral nerve tissue in order [...]

Published data on the application of the chromaticity method in analytical chemistry in the past 15 years are systematized and analyzed. Attention is focused on the analytical aspects of the chromaticity method; its capabilities, prospects for its use in analytical chemistry, and new versions of analytical signal measurements are considered. Keywords: chemical chromaticity, analytical reagents, test methods DOI: 10.1134/S1061934815100111, The requirements imposed on environmental analysis procedures become more stringent from year to year. This is true of not only the metrological characteristics but also the efficiency of routine analysis. [...]

The use of 1,2-dihydroxyanthraquinone-3-sulfonic acid sodium salt, Alizarin Red C (ARC), is considered in application to the sorption-spectrophotometry determination of organic bases novocaine and lidocaine, used as local anesthetics. The optimal conditions for the formation of all adsorbates are determined, and the equations depicting the relation between the chromaticity functions (CFs) and concentration of organic bases are found. As shown, ARC absorbs chemically on the surface of γ-[Al.sub.2][O.sub.3] as ions with the charge 2--with a predominantly vertical orientation. The calculated molar coefficients of sorbates' CFs are 200 times hugher than the ones for respective extracts. Based on the developed procedures, color scales for the rapid testing of analytes are developed. The potential use of the procedures elaborated is discussed. Keywords: sorption--spectrophotometry method, chromaticity measurements, local anesthetics, Alizarin Red C. DOI: 10.1134/S1061934812050085, In the investigation of equilibria in solutions, a wider abundance was acquired by optical techniques based on relations of absorbance to pH of solutions, as they deliver a maximum of [...]

Optimal conditions for the complexation of transition metal ions [Cu(II), Ni(II), Co(II, III), and Fe(II, III)] with 1-nitroso-2-naphthol-2,6-disulfonic acid have been determined by spectrophotometry in the presence of cationic (cetylpyridinium and cetyltrimethylammonium bromides) and nonionic (OP-10, neonol) surfactants. The introduction of nonionic surfactants does not influence the optical parameters of the system, while the introduction of cationic ones leads to hyperchromic and hypsochromic (for the system Fe(III)--NRS--surfactant) effects. The stoichiometric ratios determined by the method of isomolar series and treatment of the saturation curves of cationic surfactants at pH 4.0 are Me(II) : R : surfactant = 1 : 2 : 4, Me(III) : R : surfactant = 1 : 3 : 6. The molar absorption coefficients and chromaticity parameters of ternary complexes have been determined. A 2-5-fold increase in the molar absorption coefficients and chromaticity functions as compared to binary systems has been revealed. Keywords: surfactants, cetylpyridinium bromide, cetyltrimethylammonium bromide, OP-10, neonol, copper(II), nickel(II), cobalt(II, III), iron(II, III), 1 -nitroso-2-naphthol-3,6-disulfonic acid, spectrophotometry, chromaticity measurements. DOI: 10.1134/S1061934812040053, Complexes of metal ions with organic reagents formed in the presence of nonionic and cationic surfactants are widely used in chemical analysis [1-3]. The complexation of metal ions with chromophoric [...]

The possibility has been considered for using 1,2-dihydroxyantraquinonone-3-sulfoacid (Alizarin Red S, ARS) as a colored agent for the determination of organic bases as of their ion associates. Spectrophotometric and colorimetric properties of the ion associates of cetyltrimethylammonium bromide and local anesthetics Novocaine and Lidocaine with ARS have been studied in aqueous solutions at pH 2-6; the optimal conditions for the formation of ion associates have been determined and the extraction mechanism has been revealed. Calibration curve equations have been obtained for the dependences of the absorbance of extracts and back extracts of organic bases in aqueous and organic phases, as well as the chromaticity functions (CF) of the ion associates on the concentration of the organic bases in aqueous and organic phases. Molar absorption coefficients and CF of the considered ion associates have been determined. The advantages of the color measurement over spectrophotometry for the determination of molar absorption coefficients and CF have been demonstrated. An application of the developed procedure has been proposed. DOI: 10.1134/S1061934810090054, Optical methods based on the absorbance dependence on the pH of the solutions are widely used for studies of equilibriums in solutions, since they provide maximum information on the behavior [...]

Acid-base, spectrophotometric, and colorimetric properties of 1,2-dihydroxyantraquinonone3-sulfoacid (Alizarin Red S, ARS) have been studied in aqueous solutions at pH 3--13. Equations of calibration curves have been obtained for the dependences of absorbance and colorimetric functions (CF) on the ARS concentration. Molar absorption coefficients and CF have been determined. Dissociation constants of ARS have been determined using a spectrophotometric technique in its computational and graphical versions at an ionic strength from 0.1 to 0.5. DOI: 10.1134/S1061934810050072, In the majority of the studies of equilibria in solutions, priority is given to optical techniques, which are based on the dependences of absorbance on the pH of solution [1]. [...]

Abstract -- The stability of Analgin in aqueous acetonitrile solutions was studied depending on the concentrations of acetonitrile and stabilizer (sodium sulfite) and the pH of the solution. It was [...]

Abstract -- Optimal conditions for the complexation of iron(II, III) with 1-nitroso-2-naphthol-3,6-disulfonic acid in two buffer solutions and the reduction of iron(III) with ascorbic acid or hydroxylamine were found by [...]

Abstract -- Optical and colorimetric characteristics of 1-nitroso-2-naphthol-3,6-disulfonic acid (nitroso-R-salt) are studied in aqueous solutions at pH 4-10. Equations of calibration plots are obtained as the colorimetric functions of the [...]

Abstract -- The retention of paracetamol, propyphenazone, caffeine, phenobarbital, and codeine phosphate, which are the components of the new medicine Pentalgin, was studied by reversed-phase high-performance liquid chromatography on a [...]

Abstract -- The complexation of molybdenum(VI) and tungsten(VI) with pyrogallol red (PR) and bromopyrogallol red (BPR) in the presence of a cationic surfactant, cetylpyridinium bromide was studied. Conditions of the [...]

Abstract -- Two procedures were proposed for the quantitative analysis of the drug Pentalgin N with the use of HPLC in gradient and isocratic modes. Analgin (dipyrone), caffeine, naproxen, phenobarbital, [...]

Abstract -- The retention of analgin, caffeine, phenobarbital, and codeine--components of the medicine Pentalgin N--on a chromatographic column filled with the Nova-Pak CN HP sorbent with modifying nitrile groups as [...]

Abstract -- Two procedures were proposed for determining analgin (dipyrone), paracetamol, caffeine, phenobarbital, and codeine in the multicomponent drug Pentalgin ICN with the use of HPLC in gradient and isocratic [...]

Abstract -- The chromaticity characteristics were studied for the product of the reaction of Nessler's reagent with ammonium ions and for solutions of molecular iodine. These characteristics were used for [...]

Abstract -- The historical aspects of the synthesis, study, and application of heterocyclic azo compounds of the pyridine series in analytical chemistry are considered. The number of reagents and methods [...]

Acid-base equilibria belong to the most important and widely used equilibria in chemistry. They occur not only in the reactions between acids and bases but also in the majority of [...]

Osnovy analiticheskoi khimii (Basics of Analytical Chemistry), Zolotov, Yu.A., Ed., Moscow: Vysshaya Shkola, 2004, 2 vols., ed. 3; vol. 1: Obshchie voprosy. metody razdeleniya (General Problems. Separation Methods), 360 pp.; [...]