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  • 1
    Electronic Resource
    Electronic Resource
    Ein unabhängiges Verfahren zur Messung der Zusammensetzung von Gasgemischen mit Hilfe der Gaschromatographie (1977)
    Springer
    Pflügers Archiv 369 (1977), S. 91-94 
    Details
    ISSN: 1432-2013
    Keywords: Gas chromatography ; Gas analysis ; Determination of gas fractions ; Accuracy of the Scholander method
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The volume fraction of gas mixtures may be measured gas chromatographically by application of the 100% method, provided they can be separated. In case of gases it is not necessary to calibrate with another method. The specific character of the detector signals can be eliminated by measurements with pure components. The procedure is compared with the Scholander method. In case of O2/N2 mixtures the results agree within reproducibility, but in case of O2/CO2/N2 mixtures a systematic deviation of the CO2 fractions to smaller values is found as concerns the Scholander method. A gas mixture with 5.6 Vol% CO2 shows a difference of approximately 0.3 Vol%. The gas chromatographic method is almost 100 times as sensitive as the Scholander method. High fractions may be measured without problems and the method is not restricted to O2 and CO2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00580816
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  • 2
    Electronic Resource
    Electronic Resource
    Quantitative analyse der selbstassoziation von hämoglobinmolekülen anhand der konzentrationsabhängigkeit der spektrenHerrn Prof. Dr. Dres. h. c. G. V. Schulz zum 75. Geburtstag gewidmet (1982)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 183 (1982), S. 2599-2610 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dependence of the spectrum of oxygenated hemoglobin (Hb) on the Hb concentration was measured and it was found that Hb solutions do not obey Lambert-Beer's law. The absorption coefficient depends clearly on the Hb concentration. As all external parameters were kept constant except Hb concentration, the only way to explain our result is to assume that Hb molecules undergo self association and that this self association is reflected in the behaviour of the absorption coefficient. To get parameters which are suited to describe the self association of Hb molecules, two models were used. The first model is based on the idea that Hb associates according to the following equation: Hb + Hb ⇌ (Hb)2. Hb represents a single Hb molecule (consisting of two α-and two β-chains) and (Hb)2 a complex of two Hb molecules. The second, more complicated model, takes into account higher associates of Hb molecules (like (Hb)3, (Hb)4, . . .). By using a least square fitting, it was possible to match experimental data and theoretical curves. Furthermore it became evident that at Hb concentrations, which are of physiological relevance, about 90% of the Hb molecules are involved in self association. The second model revealed that at those Hb concentrations there is a considerable portion of complexes which are composed of 10 or more Hb molecules.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1982.021831030
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  • 3
    Electronic Resource
    Electronic Resource
    Vernetzte globuläre Proteine  -  eine neue Klasse halbsynthetischer Makromoleküle: Charakterisierung ihrer Struktur in Lösung am Beispiel hyperpolymeren Hämoglobins und Myoglobins mittels Volumenausschluß-Chromatographie, Viskosimetrie, Osmometrie und LichtstreuungProf. Dr. Dr. h. c. mult. G. V. Schulz zum 90. Geburtstag gewidmet (1996)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 197 (1996), S. 1419-1437 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Developing an artificial oxygen carrier for use in humans, we polymerize native haemoglobin and myoglobin, using bifunctional, amino group specific cross-linkers, to soluble, so-called hyperpolymers. These polymers, like other polymerized globular proteins, are members of a new class of macromolecues which consist of macromolecular base units. They all have, due to the mechanisms of the chemical reaction, broad distributions of molecular weights. Fractions of hyperpolymers of human haemoglobin were obtained by employing preparative gel-permeation (size-exclusion) chromatography. The calibration curve of analytical gel-permeation chromatography (GPC) for haemoglobin hyperpolymers was determined using mean molecular weights of some fractions, as assessed by osmometric and light scattering measurements. In analogy to native globular proteins, the calibration curve for haemoglobin polymers  -  within the range of molecular weights considered here, and within the experimental accuracy  -  is a straight line. All fractions of haemoglobin polymers were further characterized with the aid of calibrated analytical GPC. Mean non-uniformity was about, 0,6. The dependence of the logarithm of the intrinsic viscosity [η] on the logarithm of the viscosity-average molecular weight Mη of the fractions (the curve in the “structure-in-solution diagram”) also is a straight line, which is true for haemoglobin and for myoglobin polymers as well. Its first derivative is the exponent a of the Mark-Houwink function; for haemoglobin and myoglobin polymers the values are 0,39 and 0,46, respectively. Haemoglobin and myoglobin hyperpolymers, as members of the new class of polymers, both have a characteristic so-called “structure-in-solution diagram”, and a characteristic calibration curve in GPC. The special structure-in-solution of the polymer proteins is a novel molecular superstructure. The intrinsic viscosity for native myoglobin was found to be 3,5 mL/g.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1996.021970420
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  • 4
    Electronic Resource
    Electronic Resource
    Ein neuartiges Verfahren zur Bestimmung der Molmassen Breit verteilter polymerer mit Hilfe der Gelpermeations-Chromatographie und der viskosimetrie am Beispiel Hämoglobin-hyperpolymererHerrn Professor Dr. phil. Dr. h. c. mult. G. V. Schulz zum 90. Geburtstag gewidmet (1996)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 197 (1996), S. 3229-3250 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An iterative, approximative procedure is presented, to calibrate the determination of molar masses of polymers with gel-permeation chromatography, additionally using viscometry, and transformations, according to Benoit's concept of universal calibration, even if only polymers with broad molar mass distribution are available. The calculated (intermediate) values of the average molar masses from each step of iteration converge to final values. With at least two fractions of the polymers to be analyzed, and with measured intrinsic viscosities of the fractions, a calibration curve of gel-permeation chromatography and Mark-Houwink's constants can be determined. Assumptions for the use of the calibration procedure are the existence of linear calibration curves for gel-permeation chromatography, constant Mark-Houwink's exponents, and a common universal calibration curve according to Benoit, of the polymers of interest, and of another polymer for comparison. From this second polymer the Mark-Houwink equation must be known (or measurable with acceptable expense), and sufficient uniform fractions for chromatography must be available. In aqueous saline the assumptions are fulfilled by hyperpolymers of human haemoglobin, and by native proteins, as shown in a previous paper. The new procedure was applied to fractions of those hyperpolymers, it was evaluated, and variants of the procedure were compared. The evaluation was done by comparison of the number-and mass-averages of the molar masses of the fractions of haemoglobin hyperpolymers, determined with gel-permeation chromatography calibrated with the new procedure, with the values obtained from osmometry and light scattering. The goodness of the new procedure, especially the power of correction of molar masses, can be demonstrated with the application to fractions of haemoglobin hyperpolymers, it changes with their uniformity. Furthermore, the new procedure shows its efficiency, when three steps of iteration are enough to reach the final values. At last, with a Benoit transformation of the averages of molar masses, obtained by a theoretical consideration within the given marginal conditions, a rectification of the new procedure is given.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1996.021971014
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