称取样品0.200 0 g，加入盐酸-硝酸（9+1）混合酸5 mL，于沸水浴中加热2 h，冷却后加入75 g·L^-1硫脲-75 g·L^-1抗坏血酸混合溶液5 mL，混匀后，用含5 g·L^-1酒石酸的3 mol·L^-1盐酸溶液定容至25 mL，摇匀后供冷原子汞发生-原子荧光光谱法分析。所选择的仪器工作条件为：1光电倍增管负高压230 V；2主阴极峰值电流25 mA，辅助阴极峰值电流0；3 2 g·L^-1氢氧化钾-0.05 g·L^-1硼氢化钾混合液为还原剂；4载气（氩气）流量800 mL·min^-1；5原子化器温度200℃；6原子化器高度7 mm。结果表明：汞的质量在12.00 ng以内与荧光强度呈线性关系，方法的检出限（3s）为0.24 ng·g^-1。方法用于测定地球化学国家一级标准物质中的痕量汞，测定值与认定值相符，测定值的相对标准偏差（n=12）小于8.0%。

The sample (0.200 0 g) was added into 5 mL of a mixture of hydrochloric acid and nitric acid (9+1), and the solution was heated in boiling water for 2 h. After cooling, 5 mL of a solution containing 75 g·L^-1 thiourea and 75 g·L^-1 ascorbic acid was added and mixed well. Then the volume of the solution was made up to 25 mL with 3 mol·L^-1 hydrochloric acid solution containing 5 g·L^-1 tartrate. After shaking, the sample solution was used for cold atomic mercury generation-atomic fluorescence spectrometry analysis. Working conditions of the instrument were chosen as follows: 1 negative high voltage of photomultiplier tube was 230 V; 2 peak currents of main cathode and auxiliary cathode were 25 mA, 0, respectively; 3 a mixed solution containing 2 g·L^-1 KOH and 0.05 g·L^-1 KBH₄ was used as reducing agent; 4 flow-rate of carrier gas (argon) was 800 mL·min^-1; 5 temperature of atomizer was 200 ℃; 6 height of atomizer was 7 mm. It was showed that, linear relationship was found between fluorescence intensity and mass of mercury within 12.00 ng, with detection limit (3s) of 0.24 ng·g^-1. The proposed method was applied to determination of mercury in GBWs for geochemistry, giving results in consistency with certified values and RSDs (n=12) less than 8.0%.