Colorimetric Determination of Copper with Neo-Cuproine

Abstract

A rapid and accurate method has been needed for the deterruination of copper in steels, ferroalloys, and related raw materials and products. Although many methods have been proposed for the colorimetric determination of copper in such materials, most of them require a number of preliminary separations. The method proposed by Hague, Brown, and Bright (3) for the determination of copper in steels by use of sodium diethvldithiocarbamate gives good results in most cases, but the use of neo-cuproine would eliminate the addition of complexing agents to mask interfering ions, and the extraction procedure would be simplified. The possible interference of iron because of faulty extraction technique would be eliminated. Breckenridge, Lewis, and Quick (1) found, in 1939, that 2,2'-biquinoline was specific for copper. This reagent has been recommended for use in water analysis (2), but it has not been commercially available until recently. Early in 1952, Smith and McCurdy (5) reported that 2,9-dimethyl-l, 10-phenanthroline (neo-cuproine) reacts similarly with copper and that the colored system formed in isoamyl alcohol is slightly more sensitive than the 2,2'-biquinoline system. Other reagents-such as, 2,9-dimethvl-4,7-diphenyl-l,10-phenanthroline-have been suggested, but were not commercially available at the time of this work.This study was made to acquire specific information regarding the copper(I) neo-cuproine system with respect to the accuracy and precision of the system and to determine the effect of certain diverse ions, such as cyanide, fluoride, and sulfide. Early in the

Electrochemical Approach to Copper‐Catalyzed Reversed Atom Transfer Radical Cyclization

“…The copper complexes [Cu(II)L] 2+ , [ClCu(II)L] + and [Cu(I)L] + were always prepared in situ by mixing stoichiometric amounts of copper salt, amine ligand and Et 4 NCl. A stock solution of copper(I) in CH 3 CN was prepared and standardized by spectrophotometric analysis, using 2,9‐dimethyl‐1,10‐phenantroline as a specific ligand 25…”

Spectrophotometric Determination of Copper in Titanium

“…TTThereas narrowband width measurement showed the absorbance maximum to be at 457 mp (8), the use of the wide-band spectrophotometer provided maximum absorbance a t a nominal wave length of 452 mp. This setting vas used in subsequent measurements.…”

Liquid‐Liquid Extraction of Copper by Terdodecylthioglycolic Acid. Structures for the Extracted Species

“…Copper concentration in both phases was measured by colorimetric analysis using 2,9-dimethyl-1,10-phenanthroline and hydroxylamine [11]. Experimental a Metrohm Herisau E-5oo digital pH-meter, fitted with a EA 125 Metrohm combined glass pH electrode.…”

“…Experimental a Metrohm Herisau E-5oo digital pH-meter, fitted with a EA 125 Metrohm combined glass pH electrode. Copper concentration in both phases was measured by colorimetric analysis using 2,9-dimethyl-1,10-phenanthroline and hydroxylamine [11]. In order to determine the organic metal concentration, the copper was stripped from the organic phases with 1.0 moljL nitric acid.…”

“…= 2 and y should be 2.0.Therefore, the loading test and the dependency of extraction on acidity and extractant concentrations suggest the following equation for the extraction of Cu(II).---ktt Cu+ 2 + 2(HDTGh <===t CuDTGiHDTG)2 + 2H+ (11). …”