FAAS Determination Trace Amounts of Bismuth and Antimony in Crude Copper

The sample of crude copper was dissolved with HNO3,and Cu2+ ion in the sample solution was transformed into soluble complex of Cu(NH3)2+4 with excess ammonia water.Bismuth and Sb ions were enriched and separated from copper by coprecipition with ferric hydroxide and lanthanum hydroxide as carriers.Based on these facts,a method of determination of Bi and Sb in crude copper by FAAS was proposed.Experimental conditions,including the amount of conc.HCl,ferric nitrate and lanthanum nitrate added were optimized.Linear relationships between values of absorbance and mass concentration of Bi and Sb were obtained in the ranges within 10 mg·L-1 and 5 mg·L-1,with detection limits (3s) of 0.06 and 0.04 mg·L-1,respectively.Precision of the method was tested with 2 mg·L-1 of standard bismuth solution and 1 mg·L-1 of standard antimony solution,values of RSD′s (n=10) obtained were less than 2.0%.