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-GD-MS, 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.