Further studies of basic dye reagents

The work consists of a study of four types of dye, with respect to their analytical uses: the Rhodamines, Methylene Blue and its related compounds, Brilliant Green and to a lesser extent Crystal Violet. An extensive study, both literary and experimental has been performed on Methylene Blue and its 1,9 Dimethyl derivative, Taylor's Blue. A method for the determination of perchlorate with Taylor's Blue is proposed, by way of an illustration of its potential use. The butyl ester of Rhodamine B was prepared and a comparative study of its analytical properties with the parent compound was performed. A tentative method for the determination of chromium using Butyl Rhodamine B is suggested. In the course of this work, a paper chromatographic method for the separation of Rhodamines and other red basic dyes was developed and published. This method is also applicable to column chromatography using cellulose. Work was performed on the stabilities of various dye solutions, particularly with respect to the peculiarities of aqueous Brilliant Green solutions. An attempt was made to determine whether a series of onium compounds could be used as masking agents for previously developed Brilliant Green methods. Adsorption phenomena of dyes, with regard to the amount of experimental error caused in photometric determinations using such dyes, have been studied for Methylene Blue derivatives, where the potential error is found to be significant and for Brilliant Green where the error was found to be negligible in comparison with other factors. Finally, the determination of nitrate with Crystal Violet was investigated, both as a spectrophotometric method and as a possible ion-selective electrode