钼钨矿中痕量汞的微波消解-原子荧光光谱测定法

Determination of mercury in molybdenum or tungsten ore with microwave digestion and hydride generation-atomic fluorescence spectrometry

目的建立钼、钨矿中汞含量的微波消解原子荧光光谱测定方法。方法向样品中加入6 ml硝酸、4 ml氢氟酸,2 ml盐酸,放置过夜,密闭后进行微波消解,冷却至室温,在样品测定液中加入200 g/L硫脲-抗坏血酸5 ml以掩蔽铁、砷、硒等杂质离子的干扰;以2%的硼氢化钾溶液作为还原剂,5%盐酸作为载流,采用氢化物-原子荧光法测定汞浓度。结果在1.0～10.0μg/L线性范围内,所得汞的回归方程为y=422.595 5x-98.649 0,r=0.999 4,呈良好的线性关系。方法的检出限为0.005 1μg/L,平均回收率为98.4%～100.1%,RSD为1.1%～3.2%。结论该方法具有快速、准确、灵敏度高、精密度好等特点,适用于钨矿及钼矿中汞的测定。

Objective To establish the hydride generation-atomic fluorescence spectrometric method for the determination of mercury in the molybdenum or tungsten ore with microwave digestion. Methods The samples were dissolved by 6 ml nitric acid, 4 ml hydrofluoric acid and 2 ml hydrochloric acid for one night and digested by using microwave, then 5 ml 200 g/L thiourea-ascorbic acid were added to mask the interfering ions such as iron, arsenic and selenium etc. Mercury concentration was determined with hydride-generation atomic fluorescence spectrometric method with 2% sodium borohydride as the reductant in 5% hydrochioric acid media. Results The linear range of mercury was 1.0-10.0 μg/ml, the regression equation and correlation coefficients were y=422.595 5x-98.649 0,r=0.999 4,respectively. The limits of detection of mercury were 0.005 1μg/ml. The rates of recovery were 98.4%-100.1%,The relative standard deviation were 1.1%-3.2%. Conclusion This method is rapid,accurate,high sensitivity,stable and is applicable to the determination of mercury in the molybdenum or tungsten ore.