Copper detection

This dilution is effected by running the necessary volume of the saccharine liquid from a burette into a ioo c.c. flask and making up to the mark with water. The liquid thus diluted is placed in a burette and various tests made with Fehling s solution and with different volumes of the liquid, as already described (see Sugars, General Methods), until with two quantities of the liquid differing by o-i c.c., in one case only is a trace of copper detectable in the filtrate. 

Copper speciation in water was investigated by means of spectrophotometry of Cu+-bathocuprine complex formation (Bjoerklund and Morrison, 1997). The complex was separated by means of solid-phase extraction on PTFE-supported octadecyl (Qg) bonded silica discs. The discs provided rapid filtration and contributed low blanks. After filtration, the copper complex was eluted, and the copper concentration was measured by spectrophotometry. Total copper concentrations in the samples were measured after UV irradiation. The bathocuprine-available copper detection limits (for 500 ml samples) were 0.4 and 3.8 mg dm-3 copper for pure and polluted water, respectively. 

Liquid-liquid extraction has also been used in conjunction with the FIA technique in special cases to implement a particular determinative method rather than as a mere means of separating or concentrating certain species. One such method is the indirect determination of perchlorate by extraction as an ion pair with the Cu(I)-azine complex of 6-methylpicolinealdehyde. The amount of copper detected is a measure of the concentration of perchlorate in the sample [80]. 

The catalytic oxidation of the carbohydrates in the presence of Cu(II) for the detection of sucrose, galactose, and fructose was exploited using a Teflon-coated platinum wire plated with copper as the working electrode. Therefore, the addition of copper ions in the run buffer increased the sensitivity to an order of magnitude compared to run buffer without copper. Detection limits were 1 pmol 1 ... 

Amino acids, peptides, and proteins are important nutritions in foods and agricultural products. Amino acids and peptides in foods and agricultural products have been determined by CE coupled with a carbon and a copper detection electrodes. 

Franz, K. J. Hyman, L. M. Fluorescent prochelators for cellular iron and copper detection. U.S. Pat. Appl. Publ. US 20090253161,2009. 

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