FAAS Determination of Copper in Aluminum Alloys with Sensitization by Surfactant

Zinc hollow cathode lamp was used as light source in the FAAS determination of copper in aluminum alloy. The sample was dissolved in HCl and HNO3, and the determination was carried out in an acidic medium containing 3.0 mL of HNO3(1+1) per 50 mL of sample solution. 1.5 mL of 5 g·L-1 emulsifier OP solution were added as sensitizer, and 4 mL of 30 g·L-1 La(Ⅲ) solution were added as liberating agent which was used also to promote the tolerance of co-existing Si, Al, Mg, Ni, Mn, Ca, Co and Fe to significant extents. No background absorption was observed in the analysis. Linear relationship between values of absorbance and mass concentration of Cu(Ⅱ) was obtained in the range within 6.0 mg·L-1, with detection limit (3s/k) of 0.011 2 mg·L-1. An aluminum sample was analyzed by this method for its copper content, giving an average value of 1.656 mg·g-1 with value of RSD (n=6) 1.3%. By analyzing the same sample by using copper hollow cathode lamp, the av. content of Cu found was 1.670 mg·g-1 and the RSD (n=6) found was 0.92%. As shown by the result of t-test, no significant difference was found between the results using the 2 light sources.