Titrimetric Methods: Proceedings of the Symposium on Titrimetric Methods Held at Cornwall, Ontario, May 8-9, 1961

ISBN-13: 9781489927040 / Angielski / Miękka / 2013 / 185 str.

D. S. Jackson

Opis

An analysis was needed which would indicate the purity and acid content of maleic anhydride. Small amounts of acid can affect the copolymerization behavior of the anhydride 1] and may cause rearrangement and polymerization of the diene component in Diels-Alder reactions 2]. Standardized solutions of tertiary amines such as tripropylamine and N-ethylpiperidine have been used by Siggia and Floramo 1] to titrate maleic and phthalic acids in their anhydrides. This method is rather specific for maleic acid since the acids which might be included in the determination are those with dissociation constants 3 of 10-, or greater, in water. This would not include 5 acids such as succinic (dissociation constant, 7 - 10- ) 4 or fumaric (9.3 - 10- ). Anhydrides have been determined in the presence of their acids by reaction with excess aniline and deter- mination of the excess 3]. The acid content is then found by difference in anhydride and total acidity by hydrolysis. Mixtures of anhydride and acid have been determined by difference using either sodium methylate in methanol to titrate the free acid plus one equivalent per mole of the anhydride and sodium hydroxide 4], or trimethyl- benzylammonium hydroxide 5] in the presence of water to titrate the free acid plus two equivalents per mole of the anhydride. The determination of free acid by the difference in the two titrations yields poor results for samples of low acid content.

Spis treści

Electrometric Titrations.- An Automatic Wet Chemical Analyzer for Process Monitoring and Control.- The Application of Coulometric Bromination Techniques to the Determination of Unsaturated Organic Compounds.- Combined Potentiometric Determinations of Manganese, Chromium, and Vanadium in Steels.- Complexometric Titrations.- The Use of Ethylenediamine Tartrate in Polarography.- A New Instrument for Automatic Colorimetric and Fluorimetric Titrations.- Titrations in Nonaqueous Solvents.- Nonaqueous Titrations (Keynote Address).- Complex Formation of Silver Ions with Phosphorus and Nitrogen Organic Compounds in Acetone Solutions.- Alkoxides of Quaternary Ammonium Bases. A New Type of Strongly Basic Titrants.- Application of Nonaqueous Titrimetry to Pharmaceutical Analysis.- A Rapid Determination of Maleic Acid and Maleic Anhydride in Mixtures of the Two.- Titrations of 1,4-Diphenylpiperazine.