Analysis of Iron in Copper, Copper Oxide and Copper Nitrate by Solid-Phase Extraction ICP-AES Method

The reasearch shows that when the mass ratio of copper to iron is equal or greater than 100, the influence of copper on the determination of trace iron can not be ignored. To eliminate the interference, the polypropylene radical strong base anion ion exchange fiber was taken as the solid phase extraction solvent. Extraction and separation of trace iron (Ⅲ) from solution copper (Ⅱ) by the extraction solvent was studied. The extraction conditions including of adsorption and elution were optimized. The strong base anion ion exchange fiber was put into the analysis solution with the medium of 6mol/L HCl. After adsorption 1h by vibration on the oscillator, adsorptive iron(Ⅲ) was eluted with the 1mol/L HCl. The concentration of iron (Ⅲ) in the eluate solution was mesured by inductively coupled plasma atomic emission spectrometry (ICP-AES). The results showed that the residual Cu (Ⅱ) in the eluate solution did not affected the accurate determination of iron. The iron in metal copper, copper oxide and copper nitrate were separated and determinated, and the RSDs(n=3) were between 2.3% and 4.2%, the recoveries were between 96% and 103%, the detection limit of the method was 0.011μg/mL.