Yozo Koshiyama

Spectrophotometric Determination of Nitrite Ion or Chloramine T with Gallein-Molybdenum Complex and Cobalt (II) with Gallin and Hydrogen Peroxide in a Micellar Media

Abstract A simple and sensitive spectrophotometric method for the determination of nitrite ion or chloramine T is proposed utilizing a gallein-molybdenum complex in the presence of N-hexadecyltrimethylammonium chloride in acidic media. Also, a sensitive catalytic spectrophotometric procedure for determi

Spectrophotometric Study of the Effect of Cationic Micelles on the Reaction Between Gallein and Th(IV)

The acid dissociation equilibria of gallein (pyrogallolphthalein, gall), as a xanthene dye, in the presence of various surfactants--cationic, anionic, nonionic, are discussed. The coexistence of a cationic surfactant, such as hexadecyltrimethylammonium chloride (HTAC) slightly enhanced the acid dissociation, and led to a chromogenic reaction between metal ions and gall in weakly acidic media. The ternary complex between gall and Th(IV), in weakly acidic media and in the presence of N-hexadecylpyridinium chloride(HPC), was very stable with definitive spectra. However, the complex was easily decomposed in proportion to the concentration of citrate ion. Therefore, simple and rapid spectrophotometric methods for the determination of Th(IV) and citrate ion were respectively established, by using the gall-Th(IV)-HPC ternary complex in the cationic surfactant micelle. Beers law was obeyed over the range 0 to 90..mu..g of Th(IV) and 12 to 35..mu..g of citrate ion, in a final volume of 10 ml. The Sandell sensitivities were estimated to be 0.0013 ..mu..g/cm/sup 2/ Th(IV) and 0.0005 ..mu..g/cm/sup 2/ citrate ion at 600 nm. The analytical procedures were simple and did not require any organic solvent extraction.