Determination copper

In order to find optimal conditions for the soluble copper determination we examined the influence of electrolysis potential, electrolysis time, and the solution stirring rate on the accuracy and sensitivity of determination. We found that the optimal parameters for PSA determination of copper were electrolysis potential of -0.9 V vs. 3.5 mol/dm Ag/AgCl, electrolysis time of 300 s, and solution stirring rate of 4000 rpm. The soluble copper content in samples investigated in this study varied from 1.85 to 4.85 ppm. Very good correlation between the copper content determined by PSA and AAS indicated that PSA could be successfully applied for the soluble copper content determination in various dental materials. 

Figure 4. Comparison of copper determinations on our samples 1 and 2 with vcdues from 32 industrial laboratories (Ref 8, p. 268). Each x indicates one analytical result M — mean value.

Some results of the calibration uncertainty evaluation, due to the linear calibration curve of copper determination cm by molecular absorption spectro (photo)-metry using a Cecil 2020 instrument are illustrated in Table 2. Note that at the end of the linear range (0-10) mg/1 the calibration uncertainty is bigger than in the middle of the linear range for a concentration of 0.987 mg/1 copper the uncertainty component due to the calibration is 3% and for a concentration of at 6.010 mg/1 copper the uncertainty component due to the calibration is 0.56%. 

A 1-g. sample is dissolved in concentrated nitric acid, the resulting iodine removed by filtration through a sintered-glass funnel, washed with water, and the washings added to the yellow filtrate. The latter is diluted with water and the copper determined by electrolytic reduction. Anal. Calcd. for Cul Cu, 33.4. Found Cu, 33.1. 

Lead, antimony, barium, mercury, and copper determinations were done using the instrumentation, materials, and methods detailed in reference 184. All other elements were analyzed using the standard conditions as detailed in the instrument manual. 

Some examples of spectral line overlap are known.15 For example, europium at 324.7530 nm interferes in the determination of copper at 324.7540, but europium does not interfere in copper determination at 327.3962 (see Figure 5). The fact that the interference occurs only at one analytical wavelength confirms that it is spectral in nature, since the extent of physical, chemical, or ionization interferences would be similar at all wavelengths. 

F. A. Honorato, R. S. Honorato, M. F. Pimentel, M. C. U. Araujo, Analytical curve or standard addition method how to elect and design a strategy applied to copper determination in sugarcane spirits using AAS, Analyst, 127 (2002), 1520-1525. 

E. C. Silva, M. C. U. Araujo, R. S. Honorato, J. L. F. Costa Lima, E. A. Guidetti Zagatto, S. M. Boscolo Brienza, Standard additions in flow injection analysis based on merging zones and gradient exploitation application to copper determination in spirits, Anal. Chim. Acta, 319 (1996), 153-158. 

L. F. Almeida, V. Lacerda Martins, E. C. Silva, P. N. Teles Moreira, M. C. Ugolino Araujo, Implementation of an automatic standard addition method in a flow-batch system application to copper determination in an alcoholic beverage by atomic absorption spectrometry, Anal. Chim. Acta, 486 (2003), 143-148. 

Purified (1 + 30) perchloric acid for copper determination Add 10 ml of 5% APDC to 11 of (1 + 30) HC104. Mix, then extract the solution serially three times with 50 ml of MIBK to remove copper from the aqueous phase. 

Khajeh, M. Optimization of microwave-assisted extraction procedure for zinc and copper determination in food samples by Box-Behnken design. J. Food Compos. Anal. 22, 343-346 (2009)... 

Smith M. J. and Manahan S. E. (1973) Copper determination in water by standard addition potentiometry. Anal. Chem. 45, 836-839. 

Details of copper determination are also discussed by Menzies (M6) and Strasheim et al. (Sll). Elwell and Gidley (E2) examined the effect of many elements including silicon and found no interference on the absorption of copper. 

Explain how the electron configurations of chromium and copper determine that one is used to strengthen alloys and the other to make jewehy. (7.3)... 

Alloy formation was confirmed by the increase in the lattice constant of copper, determined from the Cu [111] line (Table 2), after reduction in pure hydrogen or in H -H O streams or treated at high temperature (773K). Since the lattice constant of Cu-Zn alloy is higher than that of Cu [10], the difference is ascribed to the formation of a Cu-Zn alloy. This is consistent with the presence of the peaks corresponding to Cu-Zn (20 = 42.31 and 44.51) in the XRD spectrum (Fig. 2c) of the aged catalyst. 

Turnlund JR, Keyes WR, Peiffer GL, Scott KC. Copper absorption, excretion, and retention by young men consuming low dietary copper determined by using the stable isotope 65Cu. Am J Clin Nutr 1998 67 1219-25. 

Use Colorimetry (copper determination), complex-ing agent, oxidation inhibitor in ethyl ether. 

Relative standard deviations often give a clearer picture of data quality than do absolute standard deviations. As an example, suppose that a copper determination has a standard deviation of 2 mg. If the sample has a mean value of 50 mg of... 

Unless otherwise indicated, metal content is given in micrograms per gram of protein. All zinc determinations by the dithizone method in duplicate, and in quadruplicate for the crystalline enzyme preparations. Copper determined by the sodium dithiocarbamate method. Spectrographic analyses were done in duplicate, and separately on two different instruments. 

The main interfering metals in the copper determination are Fe, Bi, Mn, Ni, Co, Cr, Mo and U, which form coloured complexes. The selectivity of the method is considerably enhanced by the use of EDTA as a masking agent. In a tartrate or citrate medium at pH 8-9, Fe, Mn, Ni and Co are masked by EDTA, as are Cd, Pb, Zn, and In, which form colourless complexes with DDTC. Of the metals forming coloured compounds with DDTC, only Bi, Tl(III), and Cu are not masked. Thallium, when reduced to T1(I), does not interfere. Bismuth can be stripped from the organic extract, containing copper and bismuth diethyidithiocarbamates, with 5 M HCl. Copper diethyidithiocarbamate is decomposed by cyanide, whereas the bismuth complex remains unaffected. 

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