不同制样方法对直流辉光放电质谱法测定氮化硼中27种杂质元素的影响  

Effect of sample preparation method on the determination of twenty-seven impurity elements in boron nitride by direct current glow discharge mass spectrometry

作　　者：谭秀珍 李瑶 朱刘 邓育宁 TAN Xiu-zhen;LI Yao;ZHU Liu;DENG Yu-ning(Guangdong First Rare Materials Co., Ltd., National Engineering and Technology Research Center of Scattered Metal, Qingyuan 511875, China;Qingyuan First Materials Co., Ltd., Qingyuan 511517,China)

机构地区：[1]广东先导稀材股份有限公司,国家稀散金属工程技术研究中心,广东清远511875 [2]清远先导材料有限公司,广东清远511517

出　　处：《冶金分析》2019年第8期23-29,共7页Metallurgical Analysis

摘　　要：讨论了3种制样方法对直流辉光放电质谱法(dc-GDMS)检测氮化硼中的Na、Mg、Al、Si等27种杂质元素的影响。3种制样方法分别如下所示:方法1,直接把氮化硼压在铟薄片上;方法2,把氮化硼压在铟薄片上后,再盖上一层铟罩;方法3,把压碎后的氮化硼放在针状钽勺上。在优化的辉光放电参数下对比了3种不同制样方法对基体信号强度的影响。试验表明:在方法1中,当氮化硼尺寸约为3mm×3mm,厚度小于1mm时,基体11B的信号可达1.8×10^7 cps;在方法2中,选择铟孔大小合适的铟罩,基体11B的信号可达1.0×10^7 cps;方法3获得基体信号强度比方法1、方法2高一个数量级。大部分元素在中分辨率下可获得较好的结果,而对于在高分辨率下也较难分离的元素,可选择丰度较低的同位素在中分辨率下进行测定,如Ge选择70 Ge^+,Se选择82 Se^+,Cd选择111 Cd^+,Sn选择119 Sn^+,Ag选择109 Ag^+,Pt选择194Pt^+。氮化硼中的杂质元素含量可通过样品片中待测元素含量减去来自于铟薄片或钽勺中该元素贡献的含量来计算获得。将样品平行测定5次,相对标准偏差均在20%以内。对于Al、Si、Ti等元素的测定,3种制样方法的测定结果基本一致;方法1、方法2中检测到的In含量较大,使得铟中的Ni、Cu对氮化硼的测定值影响较大;方法3由于钽中Fe、Cu的贡献导致氮化硼中Fe、Cu的检测值较大,但方法3获得的基体信号强度大,可降低部分元素的检出限,如Cr、Mn、Ga、Ge等。综上所述,方法3为优选方法。The influence of three sample preparation methods on the determination of twenty-seven impurity elements (including Na, Mg, Al, Si, etc) in boron nitride by direct current glow discharge mass spectrometry (dc-GDMS) was discussed. Three sample preparation methods were described as below. Method 1: the boron nitride was directly pressed on the thin sheet of indium;Method 2: after pressing boron nitride on the thin sheet of indium, a layer of indium cover was added;Method 3: the crushed boron nitride was placed on the needle-like tantalum spoon. The influence of three sample preparation methods on the signal intensity of matrix was compared under optimized glow discharge parameters. The results showed that: for Method 1, when the size of boron nitride was about 3 mm×3 mm with thickness less than 1 mm, the signal intensity of matrix (11 B) was up to 1.8×10^ 7 cps;for Method 2, if the hole size of indium cover was appropriate, the signal intensity of matrix (11 B) reached 1.0×10^ 7 cps;for Method 3, the signal intensity of matrix was one order of magnitude higher than above two methods. The analytical results were good for most elements under moderate resolution mode. For the elements which were difficult to be separated at high resolution, the isotopes with low abundance could be selected for determined at moderate resolution mode, for example, 70 Ge^+ for Ge, 82 Se^+ for Se, 111 Cd ^+ for Cd, 119 Sn ^+ for Sn, 109 Ag ^+ for Ag, and 104 Pt ^+ for Pt. The content of impurity elements in boron nitride could be calculated by subtracting the results of impurities measured from the indium sheet or tantalum spoon. The sample was determined independently for five times, and the relative standard deviations (RSD) were all less than 20%. The analysis results of Al, Si and Ti were basically consistent for three sample preparation methods. In Method 1 and Method 2, the content of detected indium was relatively high, leading to high influence of Ni and Cu in indium on the determination of boron nitride. In Method 3, due to th

关 键 词：直流辉光放电质谱法(dc-GDMS) 氮化硼 制样方法 质谱干扰 杂质元素 

分 类 号：O657.63[理学—分析化学] TF123.32[理学—化学]