Copper is an essential micronutrient for human bodies, whose distribution in different organs and tissues, metabolism and physiological impact is not thoroughly explained yet. Further issues which need clarification are the exact composition and constitution of its combinations with other elements, the physiological impact of copper and copper-enzymes in sickness and health. Biomarkers for identification of copper status are still being defined. They are necessary in order to determine the prophylactics and treatment of diseases and conditions, which are related to changes of copper concentrations in human bodies. Researches continue in an attempt to develop analytical methods for determination of copper in serum and urine, which are used in clinical laboratory diagnostics. These current developments justify the purpose of our research: to make a brief review of some issues related to studying the trace element copper. In the present paper, we have reviewed a part of the essential copper enzymes – cytochrome c oxidase, lysyl oxidase, feroxidase, monoamine oxygenase, superoxide dismutase, etc., e.g the physiological functions, which depend on the presence of these essential copper enzymes in the human organism. The issues of copper metabolism and the interactions of copper with other micronutrients (zinc, iron, vitamins A, C, E) are briefly discussed. An overview of the influence of copper on several diseases: Menkes syndrome, Wilson's disease, cardiovascular diseases, oxidative stress, osteoporosis, diabetes, chronic diarrhea, cystic fibrosis, is performed as well. The results from our study in children, aged 1 ÷ 3 years, with anemia, cystic fibrosis and chronic diarrhea and a healthy control group, showed significantly lower levels of copper in blood serum of patients as compared to controls. In conclusion , based on our brief review we might state that the results obtained from different researchers in respect of the influence of copper in different diseases and conditions are conflicting. There is a necessity of accurate and accessible methods for determination of serum copper in research and clinical biomedical laboratories. It is obvious that further research work is needed in order to clarify the contradictions and determine the role of copper in the human organism.

http://tru.uni-sz.bg/tsj/Vol9N1_2011/S.Asenova.pdf

Copper in the human organism

A new method for the determination of iron, cobalt, nickel, copper, zinc and manganese in drinking water by the reversed-phase high-performance liquid chromatography (RP-HPLC) with 2-(2-quinolinylazo)-5-diethylaminophenol (QADEAP) as precolumn derivatizing reagent was studied in this paper. The iron, cobalt, nickel, copper, zinc, and manganese ions react with QADEAP to form color chelates in the presence of cetyl trimethylammonium bromide (CTMAB) and acetic acid–sodium acetic buffer solution medium of pH 4.0. These chelates were enriched by solid-phase extraction with a Waters Nova-Pak C18 cartridge and eluted the retained chelates from the cartridge with tetrahydrofuran (THF). The enrichment factor of 100 was achieved. Then the chelates were separated on a Waters Nova-Pak C18 column (3.9 × 150 mm, 5 µm) by gradient elution with methanol (containing 0.2% of acetic acid and 0.1% of CTMAB) and 0.05 mol L−1 acetic acid-sodium acetic buffer solution (containing 0.1% of CTMAB)
(pH 4.0) as mobile phase at a flow rate of 0.5 ml min−1, and monitored with a photodiode array detector from 450∼700 nm. The detection limits (S/N = 3) of iron, cobalt, nickel, copper, zinc and manganese are 0.8, 1.1, 0.9, 1.1, 1.5 and 2.0 ng L−1, respectively, in the original sample. This method can be applied to determination at the µg L−1 level of iron, cobalt, nickel, copper, zinc and manganese in drinking water with good results.

Study on determination of iron, cobalt, nickel, copper, zinc and manganese in drinking water by solid-phase extraction and RP-HPLC with 2-(2-quinolinylazo)-5-diethylaminophenol as precolumn derivatizing reagent

Spectrophotometric determination of silver with 2-(2-quinolylazo)-5-diethylaminoaniline

Determination of transition metal ions in tobacco as their 2-(2-quinolinylazo)-5-dimethylaminophenol derivatives using reversed-phase liquid chromatography with UV-VIS detection.

Synergistic liquid-liquid extractive spectrophotometric determination of gold(III) using 1-(2',4'-dinitro aminophenyl)-4,4,6-trimethyl-1,4-dihydropyrimidine-2-thiol.

Spectrophotometric determination of copper in blood serum with 4-(2-quinolylazo)phenol

Reaction behavior of 4-(2-quinolylazo)phenol (p-QAP) is established with three noble metals, i.e. palladium(II), osmium(VIII), and gold(III), under various conditions. Palladium(II) forms a 1:1 greenish violet complex at pH 8–10 (absorption maximum at 580 nm), while osmium(VIII) forms a 1:1 violet compex at pH 8–9.5 (absorption maximum at 550 nm) with the ethanolic solution of p-QAP. Color reaction with gold(III) with ethanolic solution of p-QAP is instantaneous, but fades away with time. However, a 4:4:2 mixture of water, ethanol, and cyclohexanol stabilizes this color for 45 min. Thus a 1:1 red gold(III) complex formed at pH 8–9.5 absorbs maximum at 550 nm. The Sandell’s sensitivities (ng cm−2) of the color reactions are 2.7, 3.9, and 9.8 with palladium(II), osmium(VIII), and gold(III) respectively. Other physicochemical characteristics of the complexes are established. A number of foreign ions tested for their interferences and use of masking agents wherever necessaty it tabulated. Synthetic solutions ...

4-(2-Quinolylazo)phenol as a Spectrophotometric Reagent for Palladium(II), Osmium(VIII), and Gold(III)

Spectrophotometric micro-determination of silver(I) and iodide ions

Copper(II) interacts with 4-(l-quinolylazo)pbenol (p·QAP) to give a violet cnloured (I : 3) complex soluble in etbanolic medium. The complex exhibits maximum absorbance at 535 om In the pH range 8.0-11.1. The Sandell's sensitivity of the colour reaction is 0.0008 t'g/cm• (E=8.3X10•). The reagent has been found to be fairly selective for the determination of copper( II) in presence of various interfering metal ions. The method bas been used for tbe selective determination of copper in various milk samples.

Sudarsan Barua

Papers

Spectrophotometric determination of copper in blood serum with 4-(2-quinolylazo)phenol

4-(2-Quinolylazo)phenol as a Spectrophotometric Reagent for Palladium(II), Osmium(VIII), and Gold(III)

Spectrophotometric micro-determination of silver(I) and iodide ions

A Rapid Spectrophotometric Method for Trace Determination of Copper in Milk