火焰原子吸收光谱法测定含硅铝合金中微量铬铜镁铁

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

采用NaOH-H2O2-HNO3溶解试样，以SrCl2为释放剂，标准加入法以消除基体及试液进样的物理化学干扰，建立了火焰原子吸收光谱法连续测定Cr，Cu，Mg，Fe的方法。优化了仪器测定条件，并对可能存在的元素进行了干扰试验。结果表明，测定3μg／mLCr，Cu，10μg／mLMg和4μg／mL Fe时，100μg／mL Na^＋，K^＋，80μg／mL Ca^2＋，50μg／mL Zn^2＋，Mn^2＋，Pb^2＋，Cd^2＋和30μg／mL Ni^2＋，Co^2＋没有干扰；100μg／mL Cr，Cu，Mg，Fe之间也没有干扰。铬、铜、镁、铁的回收率为96．5％～102．4％，相对标准偏差为0．73％～2．97％。本法已用于含硅铝合金中Cr，Cu，Mg，Fe的测定，结果同分光光度法测定结果相一致。

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 SrClz solution was used as releasing agent. The standard addition method was selected to eliminate the physiochemlcal 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 Ca^2＋ , 50μg/mL Zn^2＋ , Mn^2＋ , Pb^2＋ and Cd^2＋ , 30 μg/mL Ni^2＋ and Co^2＋. 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.