ABSTRACT
To determine the concentration of copper in an unknown solution by using copper complexation, solvent extraction and spectrophotometry. Standards are used to create a calibration curve and the unknown concentration of copper is then calculated by using the linear equation from the calibration curve. The concentration of copper in the unknown solution 201 was found to be 12.57± 0.25 μg/mL.
INTRODUCTION
Copper is an essential mineral in everyday life, it is in necessary for the production of red blood and it also keeps the immune systems, nervous system ad hones healthy.[7] Too much copper in a diet can possible health risks. There are several different …show more content…
This process allows to isolate or concentrate the desired analyte or to separate it from species that would interfere in the analysis. The most used process is the extraction of an aqueous solution with an organic solvent. Diethylether, toluene, and hexane are common solvents that are immiscible with and less dense than water. They form a separate phase that floats on top of the aqueous phase. Chloroform and carbon tetrachloride are common solvents that are denser than water. In the two-phase mixture, one phase is mostly water and the other phase is mostly organic because they are immiscible liquids. Two liquids are miscible if they form a single phase when they are mixed in any ratio. However organic solvents with low polarity are generally immiscible with water. …show more content…
Ammonium citrate in the solution eliminates chemical interference from other metals by maintaining the solution at a high pH that does not allow the other metals to form complexes with the Chloroform therefore preventing them from interfering with the copper during the experiment.
Chloroform is preferred compared carbon tetrachloride since it is less toxic and preforms almost equally. Scientist preformed a series of tests where chloroform and carbon tetrachloride were used as solvents. The results indicate that the type of extraction solvent does not have a significant influence on the accuracy of determination which is why the less toxic chloroform is recommended.[3]
The transmittance is measured at 436 nm due to the copper having its maximum wavelength at 436 nm, which allows for the best absorbance and the highest accuracy of the compound as low as 10-6 g/mL