No description available.

The design and construction of a photoelectric spectrophotometer is described. The completed instrument has a wavelength reset accuracy of 1 A or less over the visible spectrum, and measures transmissions to 1 part in 500 with a bandwidth of 20-30 A. Suggestions for improved accuracy of transmission reading are included. The use of a controlled source makes an accuracy of 1 part in 10,000 theoretically attainable. This instrument was constructed so that vitamin D assay of low-potency oils could be attempted. Investigation of the antimony trichloride reaction by several authors showed that it was not suitable for this purpose. A preliminary investigation of the glycerol dichlorhydrin reaction was carried out with a Beckman model D spectrophotometer on several typical oils. It showed that this reaction was no more suitable than the other. Because of the instability of these reactions no method was found whereby increased instrument accuracy gave a corresponding increase in accuracy of assay. The only feasible method of assay for low-potency oils at present involves concentration of the vitamin D by chromatography. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

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No description available.

Thesis (M.S.)--Rochester Institute of Technology, 1989. / Includes bibliographical references (leaves 104-107).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1939. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 104-107).

Equilibrium constant (K) values for the formation of Turnbull's blue and Prussian blue have been determined spectrophotometrically at 25 ± 1°. A procedure was used which involved optical measurements in the presence of a large excess of one of the reagents so that the formation of the complex may be considered to be complete. The values of log K = 5.62 ± .03 and log K = 13.89 ± .03 for the formation of Turnbull's blue and Prussian blue, respectively, have been calculated. The ΔH° values for the reactions, Fe^3+ + Fe(CN)_6^4- = Fe^2+ + Fe(CN)_6^3- and Fe^2+ + Fe(CN)_6^3- = Fe[Fe(CN)_6^-], are used in appropriate combination with K values from the present study to calculate the thermodynamic values (ΔS° = 65.4 e.u., ΔH° = 0.55 kcal/mole, ΔG° = -18.95 kcal/mole, log K = 13.89) for Prussian blue formation (Fe^+3 + Fe(CN)_6^4- = Fe[Fe(CN)_6^-]), and to calculate the thermodynamic values ( ΔS° = -24.8 e.u., ΔG° = -7.68 kcal/mole, log K = 5.62) for Turnbull's blue formation. The replacement of the acetylacetonate ions of the bis(acetyl-acetonato)iron(II) species by cyanide ions has been studied by spectro-photometric titration, stoichiometric titration, and elemental analysis.

No description available.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1956. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 148-159).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1955. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographies: leaves 159-162, 185, 249-250.