地质试样0.100 0 g （粒径小于0.074 mm）与缓冲剂（质量分数之比为23：20：45：12：0.007的焦硫酸钾、氟化钠、氧化铝、碳和二氧化锗的混合物，其中锗为内标元素）0.100 0 g混匀后置于下电极中并压实。选择上电极的直径为4 mm，用直读发射光谱仪，按所选条件（激发电流14 A，曝光时间35 s）测定其中银、硼和锡的含量。以标准物质绘制校准曲线，上述3种元素的检出限（3s）依次为0.01，0.54，0.21 μg·g^-1。按上述方法分析了8种标准物质，上述3种元素的测定值与认定值相符，测定值的相对标准偏差（n=12）依次为2.1%~16%，5.4%~12%，5.5%~9.1%。

The geological sample (0.100 0 g, with grain size smaller than 0.074 mm) was mixed thoroughly with 0.100 0 g of a buffer mixture composing K₂S₂O₇, NaF, Al₂O₃, C and GeO₂ in the mass fraction ratio of 23:20:45:12:0.007 in which Ge acting as internal standard. The sample mixture was then added to the lower electrode and tightened. Diameter of the upper electrode selected was 4 mm. Ag, B and Sn in the sample were determined with direct reading atomic emission spectrometer under the selected conditions (excitation current:14 A; exposure time:35 s). CRM's were used for preparation of calibration curves. Values of detection limit (3s) found for the 3 elements were 0.01, 0.54, 0.21 μg·g^-1 respectively. The proposed method was tested by analyzing 8 CRM's giving results in consistency with the certified values and values of RSD's (n=12) in the ranges of 2.1%-16% (for Ag), 5.4%-12% (for B) and 5.5%-9.1% (for Sn).