Application of the Pararosaniline-Formaldehyde Spectrophotometric Method to the Determination of Sulfur in Blister and Refined Copper.

Abstract

b The sensitive pararosaniline-formaldehyde chromogenic system has been applied to the determination of sulfur as sulfur dioxide in blister and refined copper. Several factors affecting the combustion, furnace temperature, use of fluxes, and combustion accelerators and retarders have been investigated. Conditions established are quite different from those recommended by other researchers in the analysis of high melting metals and alloys. The effect of temperature on color development of the sulfonic acid derivative of prosaniline and its stability has been established for the first time. Interferences from common impurities present in copper such as selenium, tellurium, arsenic, and antimony in concentrations up to 10 times that of sulfur have been investigated. A procedure has been devised allowing accurate determination of sulfur in copper in the range 2 to 500 p.p.m. The standard deviation at the 10-p.p.m. level is less than i 1, and at the 100-p.p.m. level less than * 4.

Spectrophotometric determination of atmospheric sulfur dioxide

“…Interferences associated with the present methods for the determination of sulfur dioxide have been reviewed by Thomas (5) and by Mueller et al (6). Several investigators have suggested modifications to eliminate interferences or increase reliability (7)(8)(9)(10)(11)(12). It was decided that an investigation of important parameters and of possible modifications would be of value.…”

Voltammetric Determination of 2,6-Di-tert-Butyl-p-Cresol in Hydrocarbons.

“…Most of the previous work involving infrared measurements in polymerization kinetics entailed periodic sampling of the reaction, followed by absorption measurements of one or more reactant (s) (1). In the present study, a continuous sampling of the reacting solution is accomplished by incorporating a small monitoring pump in a closed cyclic system.…”

Light Absorption Spectrometry

“…Color measuring instruments include the Color-Eye, a tristimulus colorimeter (227), the Color-Difference Meter (225), the Tri-Color phot (410), the Gardner Model C-4 color difference meter with digital readout (171), a digital readout tristimulus integrator for the 13 and L Spectronic 505 (34), and the Elrepho (86). A direct reading CIE tristimulus colorimeter with photovoltaic cells is suitable for the continuous monitoring of color (464) A seven-fold visual colorimeter has been developed to match color difference.…”