电感耦合等离子体质谱法测定镍基高温合金中锗

镍基高温合金中的低熔点元素锗会对镍基高温合金力学性能和组织产生有害影响,因此需对其中锗的含量进行检测和严格限制。实验采用体积比为1∶1的HF-HNO₃混酸在密闭体系中微波消解样品,选择⁷²Ge作为分析同位素和动能歧视(KED)模式克服质谱干扰,采用基体匹配法绘制校准曲线和铑内标校正克服基体效应和仪器漂移的影响,建立了电感耦合等离子体质谱法(ICP-MS)测定高温合金中锗的方法。结果表明,方法线性范围为2～100 μg/L,线性相关系数(r)为1.000,检出限与定量限分别为0.036 μg/g和0.12 μg/g。按照实验方法测定镍基高温合金标准物质中的锗含量,测定结果与认定值吻合较好,相对标准偏差(RSD,n=5)小于5%。将实验方法应用于镍基高温合金样品中锗的测定并进行加标回收实验,加标回收率为100%～104%。

Determination of germanium in nickel-based superalloy by inductively coupled plasma mass spectrometry

Germanium,which is an element with low melting point,in nickel-based superalloy will cause harmful effects on the mechanical properties and microstructure of alloy.Therefore,the content of germanium should be tested and strictly limited.The sample was decomposed by microwave digestion in closed system with HF-HNO₃ mixture (volume ratio of 1∶1).The mass spectrum interference was eliminated by selecting ⁷²Ge as the analytical isotope and using kinetic energy discrimination(KED) mode.The calibration curve prepared by matrix matching method and the correction by Rh internal standard were used to overcome the influence of matrix effect and instrument drift.The determination method of germanium in nickel-based superalloy by inductively coupled plasma mass spectrometry was established.The results showed that the linear range of method was 2-100 μg/L with linear correlation coefficient (r) of 1.000.The limit of detection (LOD) and limit of quantification (LOQ) was 0.036 μg/g and 0.12 μg/g,respectively.The content of germanium in certified reference materials of nickel-based superalloy was determined according to the experimental method.The found results were in good agreement with the certified values.The relative standard deviations (RSD,n=5) were less than 5%.The proposed method was applied for the determination of germanium in nickel-based superalloy sample and the recoveries were between 100% and 104%.