Copper amalgams

The presence of trace quantities of mercury in a process stream can cause the catastrophic failure of brass heat-exchanger tubes, from the formation of a mercury-copper amalgam. Incidents have occurred where the contamination has come from unsuspected sources, such as the failure of mercury-in-steel thermometers. 

Leirskar J. 1974. On the mechanism of cytotoxicity of silver and copper amalgams in a cell culture system. Scand J Dent Res 82 74-81. 

F. Jelen, B. Yosypchuk, A. Kourdova, L. Novotny and E. Palecek, Label-free determination of picogram quantities of DNA by stripping voltammetry with solid copper amalgam mercury in the presence of copper, Anal. Chem., 74 (2002) 4788-4793. 

A modification of the electrolytic method involves the electrolysis of solutions containing both the metallic and the mercuric ions. This procedure should possibly lead to the deposition of amalgams of varying composition, but no extensive study of this sort has ever been reported. Bismuth and copper amalgams have been prepared in this manner. 

Another process for preparing hydrogen peroxide directly from dilute sulphuric acid is the subject of two patents.4 Electrolysis is conducted under high pressure inside steel cylinders, each of which is lined with a suitable cathode material, e.g. silver amalgam or copper amalgam. 

Polarographic behavior of copper(II) and copper(I) species in the presence of various ligands has been investigated (154, 215, 258, 279, 343). In some instances, however, no copper(I) intermediate was observed in the reduction to copper amalgam at the electrode, e.g., at low concentrations of 1,2-diaminoethane (270) or similar diamines (205) this is in keeping with a value of 4 x 10 for the equilibrium constant (33, 291) of the reaction... 

Section 4.1.1.2) or by contacting with mercury over 24 h [1614], Alternatively, removal of dichlorine can be achieved using a column containing metallic antimony [998]. Other methods for the removal of small quantities of Clj have employed copper amalgam, or mercury [1964]. For larger (>2%) quantities of dichlorine - ethene, ethyne or 1,3-butadiene may be introduced in the presence of ultraviolet radiation or metallic salt catalysts to scavenge the Clj [781]. 

Sn7Hg 72 phaseP Newer high copper amalgams reduce the risk of mercury release, as preferential corrosion of the p phase, CueSns, typically occursJ However, release of mercury can still occur even in these materials. Older silver-tin amalgams are based on a silver-tin alloy, while high copper amalgams are based on either a silver-copper-tin alloy or a mixture of silver-tin and silver-copper alloys. 

Traces of silver in copper amalgam [32] and in tellurium [66] have been determined by the method involving 1,10-phenanthroline and Bromopyrogallol Red. 

P. W. Alexander and U. Akapongkul, Amperometric Determination of Metal Ions in a Flow Injection System with a Copper-Amalgam Electrode. Anal. Chim. Acta, 148 (1983) 103. 

Most of them form sparingly soluble compounds with the electrode mercury and can be determined by CSV at nanomolar concentrations. At these concentrations 100-fold excess of various substances including proteins and nucleic acids have little influence on the CSV peak height of the nucleic acid bases. This makes it possible to analyze mixtures of bases with nucleic acids, the analysis of which by optical methods without separation is impossible. Sensitivity of the determination of purine and pyrimidine bases can be increased by one to three orders of magnitude if the analysis is performed in alkaline media in the presence of copper ions or at solid copper amalgam electrodes. 

In the presence of A and adenosine, the copper(II)/copper(Hg) couple split to the copper(II)/copper(I) and copper(I)/copper(Hg) couples [179, 180]. Sparingly soluble compounds of copper(I) with A and its ribonucleoside were accumulated on the electrode, either by reduction of the Cu(II) ions or by oxidation of the copper amalgam electrode. The copper(I) A deposit was stripped either cathodically or anodically. The stripping peaks obtained for copper complexes had higher detection limits, but appeared over a wider range of pH and at more negative potentials than the peaks related to mercury compounds [161]. It was shown that in addition to A, other purine bases, such as G, hypoxanthine, xanthine, and their nucleosides (guanosine and inosine) [181-183],... 

By using a copper amalgam electrode, which in effect is a copper(I)- and copper(II)-aqua ion electrode, and a pure mercury electrode, which is a redox electrode, IB remeasured and confirmed the gross complexity constant Pa and the fifth consecutive constant for the copper(II)-ammine system and provided, in addition to a number of standard redox potentials, the two step constants of the copper(I)... 

Singlet carbenes are formed by treatment of CHCI3 with t-BuOK (results in loss of HCl to give iCCy, by loss of N2 from diazo compounds, such as diazomethane (CH2N2), or by reaction of CH2I2 with zinc-copper amalgam (cyclo-propanation with the resulting CH2 synthetic equivalent, called a carbenoid, is the Simmons-Smith reaction). 

J. K. Senne and B. Kratochvil, Anal. Chem., 43, 79 (1971). Poten-tiometric study of copper (1) complexes with univalent anions in acetonitrile. The stepwise formation constants of several complexes with Cu (1) in acetonitrile were determined by potentiometric titration of Cu (1) solutions with salts of these anions using a saturated copper amalgam indicating electrode. 

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