电感耦合等离子体质谱法测定铁基非晶合金中痕量铝

采用盐硝混合酸(1+1+1)溶解样品,通过选择²⁷Al作为测定用同位素和设置中分辨率(R=4 000)消除质谱干扰,以标准加入法绘制校准曲线消除基体效应,避免了对样品基体进行分离的繁琐前处理过程,实现了电感耦合等离子体质谱法(ICP-MS)对铁基非晶合金中痕量铝的测定。实验表明,称取0.100 0 g样品于石英三角瓶中,准确加入10.0 mL盐硝混合酸(1+1+1),电热板上低温加热可将样品完全溶解;采用标准加入法建立校准曲线,相关系数为0.999 0,线性范围为0.000 1%～0.005 0%,方法的检出限为0.035 μg/g。按照实验方法,对2个铁基非晶合金样品中痕量铝进行测定,测得结果的相对标准偏差(RSD,n=9)为6.1%～7.1%,回收率为96%～106%。将实验方法与电感耦合等离子体原子发射光谱法(ICP-AES)进行方法比对,两种方法对铁基非金合金实际样品中铝的测定结果基本一致。

Determination of trace aluminium in iron-based amorphous alloy by inductively coupled plasma mass spectrometry

The sample was dissolved with mixed hydrochloric acid and nitric acid (1+1+1). The mass spectrometry interference was eliminated by selecting ²⁷Al as determination isotope and setting moderate resolution (R=4 000). The calibration curve was prepared by standard addition method to avoid the matrix effect as well as complicated pretreatment process of matrix separation. Thus, the determiantion of trace aluminum in iron-based amorphous alloy was realized by inductively coupled plasma mass spectrometry (ICP-MS). The results showed that 0.100 0 g of sample could be fully dissolved in quartz triangular flask by low temperature heating on electric hot plate with 10.0 mL of hydrochloric acid-nitric acid (1+1+1) as solvent. The calibration curve was established by standard addition method with correlation coefficient as 0.999 0 and linear range of 0.000 1%-0.005 0%. The detection limit of method was 0.035 μg/g. The experimental method was applied to the determination of trace aluminum in two iron-based amorphous alloy samples. The relative standard deviations (RSD, n=9) were between 6.1% and 7.1%, and the recoveries were between 96% and 106%. This proposed method was compared with inductively coupled plasma atomic emission spectrometry (ICP-AES), and the determination results of trace aluminum in actual iron-based amorphous alloy sample were consisit.