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Full-Text Articles in Physical Sciences and Mathematics
High Pressure Liquid Chromatographic Methods For The Separations Of Derivatized Alpha-Keto Acids And Thiamine Phosphate Esters, Bruce Clark Hemming
High Pressure Liquid Chromatographic Methods For The Separations Of Derivatized Alpha-Keto Acids And Thiamine Phosphate Esters, Bruce Clark Hemming
Theses and Dissertations
Improved methods have been developed for separation of a-keto acid derivatives and for thiamine and its phosphate esters. Linear gradient reverse phase chromatography using ion-pair formation provides baseline resolution for a seven-component homologous series of a-keto acid dinitrophenylhydrazones having increasing carbon chain lengths. Branched-chain keto acids can also be separated. Aldehyde derivatives were examined as possible interfering compounds. Peak identification in biological material was confirmed for pyruvate by an enzymic peak shift technique. Monitoring near 365 nm permits low nanogram detection. Preliminary studies of keto acids in biological material illustrate the method's applicability. The same system with slight changes separates …
The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay
The Synthesis Of Novel Macrocyclic Multidentate Compounds From Dioxodioic Acids (1), R. Elliott Asay
Theses and Dissertations
A series of novel macrocyclic multidentate crown compounds have been prepared from a series of dioxodioic acids. The dioxodioic acids were prepared by treating various oligoethylene glycols or amines with maleic, succinic, citraconic, and glutaric anhydrides. The crown compounds were then synthesized from the dioxodioic acid chlorides obtained from the diacids and various oligoethylene glycols or ethylene diamine.
A Photochemical Study Of S-Triazolo[4,3-B] Pyridazine And 3-Diazo-4-Oxo-3,4-Dihydroquinoline, John Timothy Carlock
A Photochemical Study Of S-Triazolo[4,3-B] Pyridazine And 3-Diazo-4-Oxo-3,4-Dihydroquinoline, John Timothy Carlock
Theses and Dissertations
When subjected to ultraviolet radiation in the presence of an alkene, s-triazolo[4,3-b]pyridazine (STP) undergoes an unusual 3 + 2 photocycloaddition wherein the alkene adds to the 1 and 8 positions of STP with concommitant N4-N5 bond cleavage yielding 5,6-disubstituted-6,7-dihydro-7-methylene (and 7-cyanomethyl)-5H-pyrrolo[1,2-b]-s-triazoles. Amides and esters of indole-3-carboxylic acid have been synthesized by a novel reaction employing the ultraviolet irradiation of 3-diazo-4-oxo-3,4-dihydroquinoline (QDA) in the presence of amines or alcohols respectively. QDA, when irradiated, is postulated to undergo an internal Wolff Rearrangement to Indole-3-ketene which can add any amine or alcohol to form the corresponding amide or ester in modest to good …
Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty
Real-Time Computer Optimized Scanning Potential Coulometry For Multi-Component Trace Analysis, Norman W. Petty
Theses and Dissertations
The instrumentation and methodology for real-time computer controlled scanning potential coulometry for multi-component trace analysis is described. The sensitivity limit was determined to be 10^-8 F for electrochemically reversible constituents. The sensitivity limit could be extended if measures were taken to compensate for the periodic signal found on the electrolysis current. Non-linear least squares curve fitting methods accurately resolved iron-platinum and silver-iron interferences to give accurate determinations for iron and silver. The resolving capability of this method was tested using theoretically generated scanning potential coulograms. The computer resolved sample constituents with a 1 to 100 concentration ratio and a formal …
The Dependence Of The Apparent Pk Of Ion Exchange Celluloses Of Ionic Strength, Paul Cyril Gillespie
The Dependence Of The Apparent Pk Of Ion Exchange Celluloses Of Ionic Strength, Paul Cyril Gillespie
Theses and Dissertations
Diethylaminoethyl cellulose was titrated with acid and base in various concentrations of NaCl. The pK values were determined from titration curves using a graphical technique. Two titratable groups were observed from the acid titration curve, a major and a minor group. The minor group, which represented 20% of the acid titration, was barely detectable in the base titration curve and had a salt-independent pK of 6.0. The pK of the major group was strongly salt-dependent and was approximately a linear function of log N NaCl. An equilibrium shift caused by the counter ion may explain the salt dependence. Hydrogen bonding …