HG-AFS Determination of Trace Amount of Antimony in Aluminum Alloys

Sample of aluminum alloys was dissolved in mixed acid of conc. HCl and conc. HNO3. An aliquot of the sample solution was taken and diluted to 50 mL in a volumetric flask with HCl (5+95) after adding a mixed solution of thiourea and KI. The solution was used for determination of trace amount of antimony by HG-AFS. 40 g·L-1 potassium iodide solution was suitable to be used as pre-reductant for Sb(Ⅴ),and 40 g·L-1 thiourea solution was used as complexing agent for other co-existing hydride forming elements. 20 g·L-1 KBH4 solution was used as reductant for SbH3 generation which was carried out in a medium of HCl (5+95). Linear relationship between values of fluorescence intensity and mass concentration of Sb was obtained in the range of 0.05-50.0 μg·L-1,with the detection limit (3s/k) of 0.016 μg·L-1. The proposed method was used in the analysis of 2 standard samples of aluminum alloys,giving results of Sb contents in consistency with the standard values and values of RSD′s (n=8) found were 2.14% and 3.16% respectively.