取样品0.100 g，加入2 mL盐酸、0.4 mL硝酸和4滴氢氟酸，加热溶解10 min，待冷却后，于塑料容量瓶中用水定容至50.0 mL。采用石墨炉原子吸收光谱法测定所得溶液中铊的含量，选择灰化温度为700℃，原子化温度为1 600℃，基体改进剂为200 g·L^-1酒石酸溶液。样品中铊的质量浓度在一定范围内与其吸光度呈线性关系，检出限（3S/N）为0.02 μg·L^-1。按上述方法测得标准物质的测定值与其认定值一致，测定值的相对标准偏差（n=6）在7.5%~9.9%之间。

The sample (0.100 g) was dissolved with 2 mL of hydrochloric acid, 0.4 mL of nitric acid and four drops of hydrofluoric acid by heating for 10 min. After cooling, the volume of the solution was made up to 50 mL in a plastic volumetric flask. The thallium in the solution was determined by graphite furnace atomic absorption spectrometry, at ashing temperature of 700℃, atomization temperature of 1 600℃, and 200 g·L^-1 tartaric acid was used as matrix modifier. Linear relationship between values of absorbance and mass concentration of thallium in definite ranges, with detection limit (3S/N) of 0.02 μg·L^-1. The determined results of the standard substances obtained by the proposed method were consistent with the certified values, and RSDs (n=6) were found in the range of 7.5%-9.9%.