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Papers by Raul Oteiza

Research paper thumbnail of Reaction-rate method for the determination of hydrocortisone

Analytical Chemistry, 1977

is added to hydrolysis-susceptible esters, complete hydrolysis takes place. In this case no water... more is added to hydrolysis-susceptible esters, complete hydrolysis takes place. In this case no water-free titration is necessary since all POH-groups in aqueous solution can be titrated with lye. The described method is also suitable to determine hydrolysis-susceptible samples with a high degree of accuracy. Figures 3 and 4 show conductometric titration curves. The method allows one to examine, besides phosphorous acid and its monoesters, other acids and esters also for the presence of POH groups.

Research paper thumbnail of Kinetics and mechanism of blue tetrazolium reaction with corticosteroids

Journal of Pharmaceutical Sciences, 1977

The kinetics of the reaction of blue tetrazolium with corticosteroids were investigated under pse... more The kinetics of the reaction of blue tetrazolium with corticosteroids were investigated under pseudo-first-order conditions. The reaction rates for various corticosteroids were determined at various temperatures, and the enthalpy and entropy of activation for these compounds were determined. A mechanism is proposed in which an electron pair and a proton are transferred to blue tetrazolium from the anion formed by the action of tetramethylammonium hydroxide on the alpha-carbonyl moiety of the corticosteroid. The proposed mechanism is consistent with previous experimental results.

Research paper thumbnail of Evidence for a radical chain pathway for substitution of Co2(CO)8

Journal of Organometallic Chemistry, 1980

Research paper thumbnail of Reaction-rate method for the determination of hydrocortisone

Analytical Chemistry, 1977

is added to hydrolysis-susceptible esters, complete hydrolysis takes place. In this case no water... more is added to hydrolysis-susceptible esters, complete hydrolysis takes place. In this case no water-free titration is necessary since all POH-groups in aqueous solution can be titrated with lye. The described method is also suitable to determine hydrolysis-susceptible samples with a high degree of accuracy. Figures 3 and 4 show conductometric titration curves. The method allows one to examine, besides phosphorous acid and its monoesters, other acids and esters also for the presence of POH groups.

Research paper thumbnail of Kinetics and mechanism of blue tetrazolium reaction with corticosteroids

Journal of Pharmaceutical Sciences, 1977

The kinetics of the reaction of blue tetrazolium with corticosteroids were investigated under pse... more The kinetics of the reaction of blue tetrazolium with corticosteroids were investigated under pseudo-first-order conditions. The reaction rates for various corticosteroids were determined at various temperatures, and the enthalpy and entropy of activation for these compounds were determined. A mechanism is proposed in which an electron pair and a proton are transferred to blue tetrazolium from the anion formed by the action of tetramethylammonium hydroxide on the alpha-carbonyl moiety of the corticosteroid. The proposed mechanism is consistent with previous experimental results.

Research paper thumbnail of Evidence for a radical chain pathway for substitution of Co2(CO)8

Journal of Organometallic Chemistry, 1980

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