Reinigung von Lösungsmitteln für spektroskopische Zwecke

Pestemer, Max

doi:10.1002/ange.19510630503

Cited by 112 publications

(9 citation statements)

References 21 publications

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“…The acetal is removed by heating the dioxane over sodium metal or, when present in relatively high concentrations, by refluxing the dioxane with 10% of its volume of 1 M hydrochloric acid for several hours while passing a slow stream of air (better: argon or nitrogen) through the condenser to remove the acetaldehyde formed (Ref. 18). …”

Section: Purification Of Solvents: Tetrahydrofuran and Dioxanementioning

confidence: 99%

Purification of solvents for electroanalysis: tetrahydrofuran and dioxane

Coetzee¹,

Chang²

1985

Pure and Applied Chemistry

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Section: Purification Of Solvents: Tetrahydrofuran and Dioxanementioning

confidence: 99%

Purification of solvents for electroanalysis: tetrahydrofuran and dioxane

Coetzee¹,

Chang²

1985

Pure and Applied Chemistry

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“…Purification and control of the solvents employed was made according to Pestemer (1951)_ 3) Oxidation of the coenzyme NADPH + H+ resulting in its disappearence is also a measure of changes in the quality of unsaturated fatty acids during the lipid peroxidation (Hochstein and Ernster 1963;May and McCay 1968). The -oxidation ofNADPH + H+ was followed in the system containing 2.7 ml 0.1 M phosphate buffer…”

Section: Methodsmentioning

confidence: 99%

Lipid Peroxidation in Semen of the Boar

Smutná¹,

Synek²

1979

Acta Vet. Brno

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Smutna M., o. Synek: Lipid Peroxidation in Semen of the Boar. Acta vet. Bmo, 48, 1979: 35-43. During the catalyzed aerobic incubation of the complete boar semen malonyldialdehyde (MDA) is produced. MDA is a good indicator of peroxidative decomposition of polyunsaturated fatty acids. Detection of peroxidation products was conducted both by colour reaction with 2-thiobarbituric acid (evidence of MDA), and spectrofotometrically (evidence of the conjugated dienes, oxidation of the coenzyme NADPH + H+). It was found that the progressive formation of MDA surpasses the formation of conjugated dienes especially in the early stages of peroxidation. Significant correlation for the first 30 minutes of the aerobic incubation was found between the number of spermatozoa and the amount of produced malonyldialdehyde.Enzymatic lipid peroxidation studied in isolated tails of spermatozoa was NADPH--dependent with a small dependence on pyrophosphate. Production of MDA in all studied systems was infiuenced by pH of the environment.The boar seminal plasma showed high anti-peroxidative activity limited by its dilution. Native semen, malonyldialdehyde, conjugated dienes, inhibitory effect.Properties ofthe membranes determine largely the properties of the cells and tissues. Viability of each animal cell depends on structural and functional integrity of its membrane and subcellular structures. The quality of the membrane is also important for viability of spermatozoa and for metabolic processes ensuring their contact to the environment. Changes in the properties of these membranes result in functional and morphological aberations the character of which is given by the degree of damage to the membrane.The labile compound of the membranes are unsaturated fatty acids esterified in phospholipids which together with globular proteins represent the basic structural components of all biological membrane complexes. Non-enzymatic peroxidative breakdown of unsaturated fatty acids of the membrane to small fragments impairs their function in _the lipoprotein membrane and injurs seriously their structural and functional integrity. Destruction of specific membrane phospholipids during the NADPH-induced lipid peroxidation of the microsomal fraction from rat liver was demonstrated by May and Mc Cay (1968). Decomposition by peroxidation of the chain of polyunsaturated fatty acids esterified in the beta position of phosphatidylcholine and phosphatidylethanolamine of the microsomal membrane resulted in a 40 % decrease in the amount of arachidonic acid. The harmful effect of HaO. and dialuric acid on the erythrocyte membranes in rats suffering from E hypovitaminosis lead to partial damage to phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine (Heikkila et al. 1971). Changes in the concentration of phospholipids in the boar semen were found to be caused by its aerobic incubation with Cu++ ions (Smutna 1974). Loss of plasmalogen and palmitaldehyde from the ram sperm and loss of motility of spermatozoa with their spontaneous aggluti...

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“…(1 5) Es sei noch darauf hingewiesen, daR nicht nur die 4 kinetischen GroRen (k,, und damit auch k), sondernwenn auch gewohnlich in geringerem AusmaBauch die energetischen, insbesondere die Ap-GroRen, potentialabhangig sind. Darauf soll hier nicht naher eingegangen werden.…”

Section: Zir R 7'lm Rie Der a D~~r~l I O R S V E R D R I I N~i Runclassified

Über die Wirkungsweise von Inhibitoren bei elektrochemischer Reduktion organischer Verbindungen IV. Quantitative Behandlung der Adsorptionsverdrängung

Kastening

1964

Ber Bunsenges Phys Chem

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Die in vorhergehenden Arbeiten [1–3] entwickelten Vorstellungen über die Verdrängung elektroaktiver Teilchen aus der Adsorptionsschicht durch elektroinaktive grenzflächenaktive Stoffe (Inhibitoren) als wesentliche Ursache für die hemmende Wirkung der letzteren auf den Elektrodenprozeß werden erweitert. Aus Präzisionsmessungen der Tropfzeit einer polarographischen Kapillare wird für die einzelnen Stoffe die maximale Grenzflächenkonzentration (und damit ihr Platzbedarf in der Adsorptionsschicht) ermittelt; darüber hinaus werden diesen Messungen energetische Adsorptionsparameter entnommen. Die Kenntnis des Platzbedarfs ist wichtig für die Diskussion der Abhängigkeit der Geschwindigkeitskonstanten k von der Inhibitor‐Lösungskonzentration ci entsprechend der früher experimentell gefundenen und theoretisch begründeten Beziehung k∼ci−. Mittels der energetischen Adsorptionsparameter wird der Versuch unternommen, die Absolutwirkung der einzelnen Stoffe quantitativ zu deuten, d. h. auf energetische Zusammenhänge (das unterschiedliche Adsorptionsbestreben der verschiedenen Stoffe sowie spezifische Wechselwirkungen) und kinetische Einflüsse (verursacht durch die vom Inhibitor erzwungene Orientierung des elektroaktiven Moleküls) zurückzuführen.

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Reinigung von Lösungsmitteln für spektroskopische Zwecke

Cited by 112 publications

References 21 publications

Purification of solvents for electroanalysis: tetrahydrofuran and dioxane

Purification of solvents for electroanalysis: tetrahydrofuran and dioxane

Lipid Peroxidation in Semen of the Boar

Über die Wirkungsweise von Inhibitoren bei elektrochemischer Reduktion organischer Verbindungen IV. Quantitative Behandlung der Adsorptionsverdrängung

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