直流辉光放电质谱法测定高纯二氧化锗中的16种杂质元素及其相对灵敏度因子的求取

取高纯GeO2粉末5.00g(颗粒度小于30μm)5份,其中一份作为空白,其余4份中依次加入Li、Be、Mg、Al、Ti、V、Cr、Fe、Ni、Co、Cu、Zn、Sn、Sb、Tl、Pb等16种元素的标准溶液,使其浓度梯度为0,0.4,1.0,2.0,5.0μg·g^-1,于烘箱中100℃烘干。充分研磨混匀后制得GeO2粉末中含16种杂质元素的控制样品。取高纯铟按方法规定压制成直径约为15mm的In薄片。取5片铟薄片,取适量上述5个GeO2控制样品分别置于铟薄片上,盖上数层称量纸后用手动压紧压实,使铟薄片上的控制样品的直径约为4mm,并分别进行直流辉光放电质谱法(dc-GD-MS)测定。选择放电电流为1.8mA,放电电压为850V,采用电感耦合等离子体质谱法(ICP-MS)测定控制样品中各杂质元素的含量,并将这些测定值作为标准值。将ICP-MS测定所得待测元素和基体元素的离子束强度比值为横坐标,以与其对应的信号强度为纵坐标绘制校准曲线,曲线的斜率即为各元素的相对灵敏度因子(RSF)值。所得16种元素的校准RSF(calRSF)值和仪器自带的标准RSF(stdRSF)值之间存在显著的差异,其比值大都在2~3之间。由此可见制备的一组GeO2粉末控制样品不仅建立了各元素的工作曲线,而且获得了与基体相匹配的RSF值,解决了用GD-MS测定高纯GeO2中16种杂质元素的问题。

Determination of 16 Impurity-Elements in High-Purity Germanium Dioxide by dc-GD-MS and Evaluation of Their Relative Sensitivity Factors

5 portions of high purity GeO2 powder (5.00 g for each portion, and with particle size <30 μm) were taken, with one portion as blank and in the remainder standard solutions of 16 elements (i.e., Li、Be、 Mg、 Al、Ti、V、Cr、Fe、Ni、 Co、Cu、Zn、Sn、Sb、Tl、Pb) in concentration gradient of 0, 0.40, 1.0, 2.0, 5.0 μg·g^-1 were added. Each portion was dried in an oven at 100℃, and after cooling, each portion with the added standards was mixed thoroughly by pulverizing, thus to make a set of control samples of 16 impurity-elements in GeO2. Thin indium sheets with diameters about 15 mm were made by pressing indium cubes by a hand-arbor press. Five indium sheets were taken and on each sheet, an appropriate amount of each of the control samples was added separately and covered with few pieces of weighing paper, and then pressed tightly and hardly to have the control samples adhered to the In-sheet and had their diameters about 4 mm. These control samples on the In-sheets were analyzed by dc-GDMS , under the conditions of discharge current of 1.8 mA and discharge voltage of 850 V. Simultaneously, the 16 elements in the 5 GeO2 control samples were determined by ICP-MS and the results obtained were taken as standard values. Calibration curves were prepared by taking ratios of intensities of ionic beams of the elements determined to that of the matrix element as abscissa and taking the respective signal intensities as ordinate, and values of slopes of each of the 16 calibration curves were taken as the calibrated RSF for these elements. Significant differences were found between the values of calRSF and values of stdRSF carried with the instrument of GD-MS, with their ratios between 2 . 3. It was obvious that the preparation of a set of control samples of high-purity GeO2 giving known values of 16 impurity elements and the finding of calRSF for the 16 elements makes it possible to obtain quantitative results by GD-MS.