Use Of Cumene Hydroperoxide As An End-point Indicator In The Titration Of Bases By Catalytic Thermometric Titrimetry

The use of the decomposition reaction of cumene hydroperoxide for indication of the end-point of the titration of organic bases with perchloric acid was investigated. The rise in temperature at the end-point is of the order of 25°C. Only strong bases can be determined when the titrand solvent is acetic acid - acetic anhydride (92 + 8 v/v), but even weak bases such as caffeine can be determined in 1,2-dichloroethane. Some titration curves resulting from titration of bases with boron trifluoride (a Lewis acid) are presented.115676176

Titration Of Proteins In Dimethyl Sulphoxide-water Mixtures

The acid-base behaviour of arginine, lysozyme and ovalbumin has been studied by potentiometric and catalytic thermometric titrimetry in a mixture of dimethyl sulphoxide-water, with acrylonitrile as the end-point indicator in the latter technique. It was observed that, with the exception of the SH groups, all the protonated groups, including the guanidine groups of lysozyme and ovalbumin, were titrated by catalytic thermometric titrimetry. By using potentiometric titrimetry, all the titratable groups of ovalbumin were determined, whereas the guanidine groups of lysozyme were not determined by this technique.116111181118

Characterization And Determination Of Titratable Groups Of Proteins By Linearization Of Titration Curves. I. Application To Ovalbumin

A study involving the use of potentiometric base titration of fully protonated protein to characterize and to determine their titratable groups has been performed. This has been done by using the plots obtained by linearization of titration curve of ovalbumin. Linear plots corresponding to two different types of carboxilic groups, to the imidazol group and to the amino groups with pKa values of 3.48, 5.15, 7.33, and 10.06, respectively, have been obtained. The number of moles of each titratable group found per mole of ovalbumin are 27.3 and 15.9 for the two carboxilic groups, 3.7 for the imidazol group, and 12.8 for the amino groups. © 1981.1122323328Gran, Determination of the Equivalent Point in Potentiometric Titrations. (1950) Acta Chemica Scandinavica, 4, pp. 559-577Gran, (1952) Analyst (London), 77, pp. 661-671Ingman, Still, (1966) Talanta, 13, pp. 1431-1442Ivaska, (1974) Talanta, 21, pp. 1167-1181Ivaska, Wanninen, Potentiometric Titration of Weak Acids (1973) Analytical Letters, 6 (11), pp. 961-967Mc Callum, Midgley, (1975) Anal. Chim. Acta, 78, pp. 171-181Mc Callum, Midgley, Linear titration plot for resolving mixtures of weak acids by potentiometric titration (1976) Analytical Chemistry, 48, pp. 1232-1235Briggs, Stuehr, (1974) Anal. Chem, 46, pp. 1517-1521Ivaska, Harju, (1975) Talanta, 22, pp. 1051-1052Seymour, Clayton, Fernando, Determination of pKa values of acid components in atmospheric condensates by linearization of segmented titration curves (1977) Analytical Chemistry, 49, pp. 1429-1432Lindstrøm-Lang, (1924) Rec. Trav. Lab. Carlsberg, 7, p. 15Tanford, The Interpretation Of Hydrogen Ion Titration Curves Of Proteins (1962) Advan. Protein Chem, 17, p. 69Steinhardt, Beychok, (1964) The Proteins, 2, pp. 139-303. , H. Neurath, R.L. Hill, Academic Press, New YorkKolthoff, Sandell, (1967) Textbook of Quantitative Inorganic Analysis, p. 562. , Macmillan, New YorkCannan, Kibrick, Palmer, THE AMPHOTERIC PROPERTIES OF EGG ALBUMIN (1941) Annals of the New York Academy of Sciences, 41, pp. 243-266Jespersen, Jordan, Thermometric Enthalpy Titration of Proteins (1970) Analytical Letters, 3 (6), pp. 323-334Vickery, Shore, The basic amino-acids of crystalline egg-albumin. (1932) Biochem J, 26, p. 1101Cannan, (1942) Chem. Rev, 30, p. 395Levy, (1958) C. R. Trav. Lab. Carlsberg, 30, p. 291Marini, Marti, (1980) Biopolymers, 19, pp. 885-898Marini, Martin, Evaluation of the Electrostatic Interaction Parameter on a Simulated Protein Titration Curve (1980) Analytical Letters, 13 (2 B), pp. 93-10

An Experiment Illustrating Countercurrent Chromatography With Simple Apparatus

[No abstract available]52425825

Implications Of Ignoring Electrostatic Interaction On Simulated And Experimental Protein Titration Curves

[No abstract available]291135141Linderstrom-Lang, (1924) Rec. Trav. Lab. Carlsberg, 15 (7)Cannan, (1942) Chem. Rev., 30, p. 395Kenchington, Ward, (1954) Biochem. J., 58, p. 202Levy, (1958) C.R. Trav. Lab. Carlsberg, 30, p. 291Godinho, Aleixo, (1981) Anal. Biochem., 112, p. 323Kaarsholm, Schack, Ionization Behavior of Papaya Peptidase A and Its Succinylated Derivative. (1984) Acta Chemica Scandinavica, 38 B, p. 225Marini, Martin, Evaluation of the Electrostatic Interaction Parameter on a Simulated Protein Titration Curve (1980) Analytical Letters, 13 (2 B), p. 93Aleixo, Godinho, da Costa, (1992) Anal. Chim. Acta, 257, p. 35Godinho, de Souza, Aleixo, Ivaska, (1988) J. Assoc. Off. Anal. Chem., 71, p. 1028Canfield, (1963) J. Biol. Chem., 238, p. 2698Nisbet, Saundry, Moir, Fothergill, Fothergill, (1981) Eur. J. Biochem., 115, p. 335Inada, (1961) J. Biochem. (Tokyo), 49, p. 217Tojo, Hamaguchi, Imanishi, Amano, (1966) J. Biochem. (Tokyo), 60, p. 13

Cykle-Skat i Frankrig.

A method for determination of azide, based on the thermometric titration of this anion with hydrochloric acid, is described. Although this reaction has a large enthalpy change (ΔH = -3.6 kcal/ mole), sulphate is added as an endothermic thermometric indicator to improve the end-point. The application of the method to the analysis of insoluble azides has been studied. © 1977.249593594Kolthoff, Sandell, (1967) Textbook of Quantitative Inorganic Analysis, , 3rd Ed., Macmillan, New YorkCoetzee, (1961) Treatise on Analytical Chemistry, 3. , 3rd Ed., Interscience, New York, Part IIPristera, (1971) Encyclopedia of Industrial Chemical Analysis, 12. , F.D. Snell, L.S. Ettre, Wiley-Interscience, New Yor

Potentiometric Study Of Acid-base Properties Of Humic Acid Using Linear Functions For Treatment Of Titration Data

A pontentiometric study of the acid-base properties of humic acid was made with the objective of determining the pKa value and concentration of each titratable group. The use of linear equations in the treatment of titration curves led to the characterization of six titratable groups, which permits the acid-base properties to be explained and will be useful in studies of soil and environmental chemistry. © 1992.25713539Takamatsu, Yoshida, DETERMINATION OF STABILITY CONSTANTS OF METAL-HUMIC ACID COMPLEXES BY POTENTIOMETRIC TITRATION AND ION-SELECTIVE ELECTRODES (1978) Soil Science, 125, p. 377Perdue, Reuter, Ghosal, (1980) Geochim. Cosmochim. Acta, 44, p. 1841Paxéus, Wedborg, (1985) Anal. Chim. Acta, 169, p. 87Leunberger, Schindler, Application of integral pk spectrometry to the titration curve of fulvic acid (1986) Analytical Chemistry, 58, p. 1471Andres, Romero, Gavilan, (1987) Talanta, 34, p. 583Schnitzer, Goshi, (1979) J. Indian Chem. Soc., 61, p. 1090Godinho, Aleixo, (1981) Anal. Biochem., 112, p. 323Godinho, Aleixo, Hora Alves, (1982) Anal. Biochem., 123, p. 244Godinho, Aleixo, Hora Alves, (1985) An. Acad. Brasil. Ciênc., 57, p. 305Aleixo, Godinho, (1987) Quim. Nova., 10, p. 83Seymour, Clayton, Fernando, Determination of pKa values of acid components in atmospheric condensates by linearization of segmented titration curves (1977) Analytical Chemistry, 49, p. 1429Pehrsson, Ingman, Johansson, (1976) Talanta, 23, p. 769Feuerstein, Eberlet, (1979) Naturwissenschaften, 66, p. 572Perdue, (1978) Geochim. Cosmochim. Acta, 42, p. 1351Ephraim, Marinsky, (1986) Environ. Sci. Technol., 20, p. 354Tipping, Reddy, Hurley, (1990) Environ. Sci. Technol., 24, p. 170

Characterization And Determination Of Titratable Groups Of Proteins By Linearization Of Titration Curves. Ii. Application To Lysozyme

The potentiometric acid-base titration curve of fully protonated lysozyme at ionic strengths of 0.10 and 1.0 m has been performed. The stoichiometry and the pKa values of each titratable group have been determined through the linearization of titration curves. Two types of carboxylic groups with pKa values of 3.76 and 5.02, the imidazole group with pKa 7.37 and the amine group with pKa 9.63, have been identified at an ionic strength of 0.10 m at 25.0°C. The number of titratable groups found per mole of protein has been 5.12 and 5.60 for the two types of carboxylic groups, 1.13 for the imidazole group, and 3.19 for the amino groups. The endpoint of the titration of the protein obtained by this method accords quite well with the endpoint obtained by the use of Gran function applied to the excess of strong base. © 1982.1232244248Godinho, Aleixo, (1981) Anal. Biochem, 112, pp. 323-328Cannan, Kibrick, Palmer, THE AMPHOTERIC PROPERTIES OF EGG ALBUMIN (1941) Annals of the New York Academy of Sciences, 41, pp. 243-266Tanford, Wagner, (1954) J. Amer. Chem. Soc, 76, pp. 3331-3336Beichok, Warner, Denaturation and Electrophoretic Behavior of Lysozyme1,2 (1959) Journal of the American Chemical Society, 81, pp. 1892-1897Pehrsson, Ingman, Axel, (1976) Talanta, 23, pp. 769-780Gran, (1952) Analyst (London), 77, pp. 661-671Canfield, (1963) J. Biol. Chem, 238, pp. 2698-2707Nozaki, Tanford, (1967) J. Biol. Chem, 242, pp. 4731-4735Godinho, O. E. S., Aleixo, L. M., and Hora Alves, J. P, paper to be publishe

Investigation Of The Effects Of Dilution And Number Of Points In The Performance Of A Linear Method Of Potentiometric Titration Of Weak Bases

[No abstract available]352153156Barry, Meites, Titrimetric applications of multiparametric curve fitting. I. Potentiometric titrations of weak bases with strong acids at extreme dilutions (1974) Anal. Chim. Acta, 68, pp. 435-445Briggs, Stuehr, Simultaneous determination of precise equivalence points and pK values from potentiometric data: Single pK systems (1974) Anal. Chem, 46, pp. 1517-1521Godinho, Aleixo, Characterization and determination of titratable groups of proteins by linearization of titrations curves (1981) Anal. Biochem, 112, pp. 323-328Gran, Determination of the equivalence point in potentiometric titrations I (1950) Acta Chemica Scandinavica, 4, pp. 559-577Gran, Determination of the equivalence point in potentiometric titrations. II (1952) Analyst (London), 77, pp. 661-671Hofstee, Nonlogarithmic linear titrations curves (1960) Science, 131, p. 39Ingman, Still, Graphic method for the determination of titration end-points (1966) Talanta, 13, pp. 1431-1442Ivaska, Wanninen, Potentiometry titration of weak acids (1973) Analytical Letters, 6 (11), pp. 961-967Murtlow, Meites, Titrimetric applications of multiparametric curve fitting. VI. Determination of strong acids in the presence of weak acids by potentiometric titration (1977) Anal. Chim. Acta, 92, pp. 285-291Seymour, Clayton, Fernando, Determination of pKa values of acid components in atmospheric condensates by linearization of segmented titration curves (1977) Analytical Chemistry, 49, pp. 1429-1432Yasuda, Yamsaki, Ohtaki, Stability of complexes of several carboxylic acids with bivalent metals (1960) Bulletin of the Chemical Society of Japan, 23, pp. 1067-107

A Device For Stepwise Addition Of Titrant In Automated Potentiometric Titrations

A microcomputer-based liquid-propulsion system is described for the stepwise addition of titrant. It is capable of supplying up to six titration cells simultaneously. In titrations of 0.01 M hydrochloric acid with 0.1 M sodium hydroxide, the relative standard deviation was ± 0.1% and the error was +0.2%. © 1989.2221379384Smit, Smit, (1982) Anal. Chim. Acta, 143, p. 45Smit, Smit, Steigstra, Hannema, (1982) Anal. Chim. Acta, 143, p. 79Stur, Bos, van der Linden, (1984) Anal. Chim. Acta, 158, p. 93Stur, Bos, van der Linden, (1984) Anal. Chim. Acta, 158, p. 125Arnold, Daignault, Rabenstein, (1985) Anal. Chem., 57, p. 1112Arena, Rizarelli, Sammartano, Rigano, (1979) Talanta, 26, p. 1Ivaska, Nagypál, (1980) Talanta, 27, p. 721Meites, Stuer, Briggs, (1975) Anal. Chem., 47, p. 1485Godinho, de Souza, Aleixo, Ivaska, (1988) J. Assoc. Off. Anal. Chem., 71, p. 1028Godinho, Aleixo, (1981) Anal. Biochem., 112, p. 323Gran, (1952) Analyst, 77, p. 66