Determination of micro chromium,copper,magnesium and iron in silicon aluminum alloy by flame atomic absorption spectrometry

A new method for the determination of micro Cr,Cu,Mg and Fe by flame atomic absorption spectrometry(FAAS) was developed.Sample was dissolved in a mixture of NaOH,H2O and HNO3.The SrCl2 solution was used as releasing agent.The standard addition method was selected to eliminate the physiochemical influence and disturbance from matrix effect and sample injection.In the determination of 3 μg/mL Cr and Cu,10 μg/mL Mg and 4 μg/mL Fe,there is no interference from 100 μg/mL Na+ and K+,80 μg/mL Ca2+,50 μg/mL Zn2+,Mn2+,Pb2+ and Cd2+,30 μg/mL Ni2+ and Co2+.Cr,Cu,Mg,Fe at 100 μg/mL do not interfere each other as well.The method has been used to the determination of Cr,Cu,Mg and Fe in silicon aluminum alloy with the recovery of 96.5%-102.4% and the relative standard deviation of 0.73%-2.97%.The results are consistent with those of spectrophotometry.